SSAT Middle Level Reading : Main Idea, Details, Opinions, and Arguments in Narrative Science Passages

Study concepts, example questions & explanations for SSAT Middle Level Reading

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Example Questions

Example Question #1 : Locating Details In Narrative Science Passages

Adapted from "The Man-Like Apes" by T. H. Huxley in A Book of Natural History (1902, ed. David Starr Jordan)

The orangutan is found only in Sumatra and Borneo, and is common in either of these islands—in both of which it occurs always in low, flat plains, never in the mountains. It loves the densest and most sombre of the forests, which extend from the seashore inland, and thus is found only in the eastern half of Sumatra, where alone such forests occur, though, occasionally, it strays over to the western side. On the other hand, it is generally distributed through Borneo, except in the mountains, or where the population is dense. In favorable places the hunter may, by good fortune, see three or four in a day.

Except in the pairing time, the old males usually live by themselves. The old females and the immature males, on the other hand, are often met with in twos and threes, and the former occasionally have young with them, though the pregnant females usually separate themselves, and sometimes remain apart after they have given birth to their offspring. The young orangs seem to remain unusually long under their mother’s protection, probably in consequence of their slow growth. While climbing, the mother always carries her young against her bosom, the young holding on by the mother’s hair. At what time of life the orangutan becomes capable of propagation, and how long the females go with young is unknown, but it is probable that they are not adult until they arrive at ten or fifteen years of age. A female which lived for five years at Batavia had not attained one-third the height of the wild females. It is probable that, after reaching adult years, they go on growing, though slowly, and that they live to forty or fifty years. The Dyaks tell of old orangs that have not only lost all their teeth, but which find it so troublesome to climb that they maintain themselves on windfalls and juicy herbage.

Why is the orangutan found only in the eastern half of Sumatra?

Possible Answers:

None of these answers is correct

Because this is the furthest away from human settlements

Because this is where the orangutans can find the most food

Because this is where the thickest forest cover is found

Because this is where the mountains are predominantly found

Correct answer:

Because this is where the thickest forest cover is found

Explanation:

This question requires little more than reading in detail and understanding the meaning of the word “densest.” When used to describe forests, the word “dense” means thick with trees. Regarding where the orangutan is found in Sumatra, the author says “It loves the densest and most sombre of the forests . . . and thus is found only in the eastern half of Sumatra, where alone such forests occur." Although it might also be true that these places are furthest from human settlements and are places where the orangutans can find the most food, these answers are not explicitly stated in the text and are therefore less correct.

Example Question #21 : Main Idea, Details, Opinions, And Arguments In Narrative Science Passages

Adapted from "The Man-Like Apes" by T. H. Huxley in A Book of Natural History (1902, ed. David Starr Jordan)

The orangutan is found only in Sumatra and Borneo, and is common in either of these islands—in both of which it occurs always in low, flat plains, never in the mountains. It loves the densest and most sombre of the forests, which extend from the seashore inland, and thus is found only in the eastern half of Sumatra, where alone such forests occur, though, occasionally, it strays over to the western side. On the other hand, it is generally distributed through Borneo, except in the mountains, or where the population is dense. In favorable places the hunter may, by good fortune, see three or four in a day.

Except in the pairing time, the old males usually live by themselves. The old females and the immature males, on the other hand, are often met with in twos and threes, and the former occasionally have young with them, though the pregnant females usually separate themselves, and sometimes remain apart after they have given birth to their offspring. The young orangs seem to remain unusually long under their mother’s protection, probably in consequence of their slow growth. While climbing, the mother always carries her young against her bosom, the young holding on by the mother’s hair. At what time of life the orangutan becomes capable of propagation, and how long the females go with young is unknown, but it is probable that they are not adult until they arrive at ten or fifteen years of age. A female which lived for five years at Batavia had not attained one-third the height of the wild females. It is probable that, after reaching adult years, they go on growing, though slowly, and that they live to forty or fifty years. The Dyaks tell of old orangs that have not only lost all their teeth, but which find it so troublesome to climb that they maintain themselves on windfalls and juicy herbage.

Which of these pieces of information does the author know with certainty?

Possible Answers:

How long orangutans are cared for by their mothers

That orangutans grow reasonably slowly

How long orangutans live

When orangutans stop growing

When orangutans reach full sexual maturity

Correct answer:

That orangutans grow reasonably slowly

Explanation:

When talking about the longevity and life spans of orangutans in the second paragraph, the author makes a lot of statements based on conjecture as opposed to certainty. He says, “At what time of life the orangutan becomes capable of propagation, and how long the females go with young is unknown, but it is probable that they are not adult until they arrive at ten or fifteen years of age.” This tells us that he does not know with certainty “when orangutans reach sexual maturity” or “how long orangutans are cared for by their mothers.” He also says “It is probable that, after reaching adult years, they go on growing, though slowly, and that they live to forty or fifty years.” This tells us that what the author believes about orangutans is merely “probable” and that he does not know “how long orangutans live” or “when orangutans stop growing.” All he seems to know with certainty is that they “grow reasonably slowly"; this is shown by the previous excerpt and the quotation “the young orangs seem to remain unusually long under their mother’s protection, probably in consequence of their slow growth.” The “probably” here applies to the reason why they remain so long under their mother’s protection, not the veracity of their slow growth.

Example Question #33 : Ideas In Science Passages

Adapted from "How the Soil is Made" by Charles Darwin in Wonders of Earth, Sea, and Sky (1902, ed. Edward Singleton Holden)

Worms have played a more important part in the history of the world than most persons would at first suppose. In almost all humid countries they are extraordinarily numerous, and for their size possess great muscular power. In many parts of England a weight of more than ten tons (10,516 kilograms) of dry earth annually passes through their bodies and is brought to the surface on each acre of land, so that the whole superficial bed of vegetable mould passes through their bodies in the course of every few years. From the collapsing of the old burrows, the mold is in constant though slow movement, and the particles composing it are thus rubbed together. Thus the particles of earth, forming the superficial mold, are subjected to conditions eminently favorable for their decomposition and disintegration. This keeps the surface of the earth perfectly suited to the growth of an abundant array of fruits and vegetables.

Worms are poorly provided with sense-organs, for they cannot be said to see, although they can just distinguish between light and darkness; they are completely deaf, and have only a feeble power of smell; the sense of touch alone is well developed. They can, therefore, learn little about the outside world, and it is surprising that they should exhibit some skill in lining their burrows with their castings and with leaves, and in the case of some species in piling up their castings into tower-like constructions. But it is far more surprising that they should apparently exhibit some degree of intelligence instead of a mere blind, instinctive impulse, in their manner of plugging up the mouths of their burrows. They act in nearly the same manner as would a man, who had to close a cylindrical tube with different kinds of leaves, petioles, triangles of paper, etc., for they commonly seize such objects by their pointed ends. But with thin objects a certain number are drawn in by their broader ends. They do not act in the same unvarying manner in all cases, as do most of the lower animals.

Which of worms' sensory organs is well-developed?

Possible Answers:

Hearing

Smell

Taste

Touch

Sight

Correct answer:

Touch

Explanation:

This question requires little more than careful reading in detail. In the second paragraph, the author says, “Worms are poorly provided with sense-organs, for they cannot be said to see, although they can just distinguish between light and darkness; they are completely deaf, and have only a feeble power of smell; the sense of touch alone is well developed.” So, they cannot hear at all, and cannot see or smell well. Their sense of taste is unmentioned, but the author says “the sense of touch alone is well developed.”

Example Question #5 : Identifying And Analyzing Details In Science Passages

Adapted from "Birds’ Nests" by John Burroughs in A Book of Natural History (1902, ed. David Starr Jordan)

The woodpeckers all build in about the same manner, excavating the trunk or branch of a decayed tree, and depositing the eggs on the fine fragments of wood at the bottom of the cavity. Though the nest is not especially an artistic work, requiring strength rather than skill, yet the eggs and the young of few other birds are so completely housed from the elements, or protected from their natural enemies—the jays, crows, hawks, and owls. A tree with a natural cavity is never selected, but one which has been dead just long enough to have become soft and brittle throughout. The bird goes in horizontally for a few inches, making a hole perfectly round and smooth and adapted to his size, then turns downward, gradually enlarging the hole, as he proceeds, to the depth of ten, fifteen, twenty inches, according to the softness of the tree and the urgency of the mother bird to deposit her eggs. While excavating, male and female work alternately. After one has been engaged fifteen or twenty minutes, drilling and carrying out chips, it ascends to an upper limb, utters a loud call or two, when its mate soon appears, and, alighting near it on the branch, the pair chatter and caress a moment; then the fresh one enters the cavity and the other flies away.

Which of these statements is NOT supported by the passage?

Possible Answers:

Woodpeckers prefer to build their nests in living trees.

Woodpeckers have many natural enemies and rivals.

Woodpeckers have to be relatively strong, when compared to other birds, to build their nests.

Female and male woodpeckers work together.

All of these statements are supported by the passage.

Correct answer:

Woodpeckers prefer to build their nests in living trees.

Explanation:

The author tells you that woodpeckers like to build their nests in “decaying” trees, so you can reliably claim that they do not “prefer to build their nests in living trees.” This is also supported by the author when he says, “A tree with a natural cavity is never selected, but one which has been dead just long enough to have become soft and brittle throughout.” That male and female woodpeckers work together is supported by the information at the end of the passage. That woodpeckers have to be strong is supported by the author’s claim that nest building requires strength rather than skill. Finally, that woodpeckers have many natural rivals is supported by the statement “protected from their natural enemies—the jays, crows, hawks, and owls.”

Example Question #22 : Main Idea, Details, Opinions, And Arguments In Narrative Science Passages

Adapted from "The Greatest Sea-Wave Ever Known" by R. A. Proctor in Wonders of Earth, Sea, and Sky (1902, ed. Edward Singleton Holden)

The inhabitants of the Sandwich Islands, which lie about six thousand three hundred miles from Arica—a city in Chile, might have imagined themselves safe from any effects that could be produced by an earthquake taking place so far away from them. But on the night between August 13th and 14th, the sea around this island group rose in a surprising manner, and many thought the islands were sinking, and would shortly subside altogether beneath the waves. Some of the smaller islands, indeed, were for a time completely submerged. Before long, however, the sea fell again, and as it did so the observers "found it impossible to resist the impression that the islands were rising bodily out of the water." For no less than three days this strange oscillation of the sea continued to be experienced, the most remarkable ebbs and floods being noticed at Honolulu, on the island of Woahoo.

But the sea-wave swept onward far beyond these islands. At Yokohama, in Japan, more than ten thousand five hundred miles from Arica, an enormous wave poured in on August 14th, but at what hour we have no satisfactory record. So far as distance is concerned, this wave affords most surprising evidence of the stupendous nature of the disturbance to which the waters of the Pacific Ocean had been subjected. The whole circumference of the earth is but twenty-five thousand miles, so that this wave had traveled over a distance considerably greater than two-fifths of the earth's circumference. A distance which the swiftest of our ships could not traverse in less than six or seven weeks had been swept over by this enormous undulation in the course of a few hours.

The earthquake that produced the sea-wave took place in __________.

Possible Answers:

an unknown location somewhere in the Pacific Ocean

Arica

the Sandwich Islands

Yokohama

Honolulu

Correct answer:

Arica

Explanation:

The earthquake that produced the sea-wave originated in Arica, a city in Chile. The biggest clue that helps you determine this is the fact that the author is trying to highlight the vast distances traveled by the sea-wave by mentioning how far apart everything touched by the sea-wave is. Most of the places that are mentioned are described in relation to their distance from Arica. This suggests that Arica was the point where the wave began. This can be most clearly seen in the introduction, where the author says, “The inhabitants of the Sandwich Islands, which lie about six thousand three hundred miles from Arica—a city in Chile, might have imagined themselves safe from any effects which could be produced by an earthquake taking place so far away from them.”

Example Question #21 : Main Idea, Details, Opinions, And Arguments In Narrative Science Passages

Adapted from "What I Saw in an Ant’s Nest" by Andrew Wilson in A Book of Natural History (1902, ed. David Starr Jordan)

The workers appear to perform a never-ending round of duties. They build the nests, make the roads, attend to the wants of the young, train up the latter in the ways of ant existence, wait on the sovereigns of the nest, and like diplomatic courtiers, duly arrange for the royal marriages of the future. As Mr. Bates remarks, “The wonderful part in the history of the termites is that not only is there a rigid division of labor, but that nature has given to each class a structure of body adapting it to the kind of labor it has to perform. The males and females form a class apart; they do no kind of work, but in the course of growth, acquire wings to enable them to issue forth and disseminate their kind. The workers and soldiers are wingless, and differ solely in the shape and armature of the head. The head in the laborers is smooth and rounded, the mouth being adapted for the working of the materials in building the hive. In the soldier, the head is of very large size, and is provided in almost every kind with special organs of offense and defense in the form of horny processes resembling pikes, tridents, and so forth . . . The course of human events in our day seems, unhappily, to make it more than ever necessary for the citizens of industrious communities to set apart a numerous armed class for the protection of the rest; in this, nations only do what nature has of old done for the termites. The soldier termite, however, has not only the fighting instinct and function; he is constructed as a soldier, and carries his weapons not in his hand but growing out of his body.” When a colony of termites is disturbed, the ordinary citizens disappear and the military are called out. “The soldiers mounted the breach,” says Mr. Bates, “to cover the retreat of the workers,” when a hole was made in the archway of one of their covered roads, and with military precision the rear men fall into the vacant places in the front ranks as the latter are emptied by the misfortune of war.

Which of these is not a duty of the worker ants?

Possible Answers:

Caring for the young

Road construction

Nest building

Waiting on the ruling ants

Protecting the colony from attack

Correct answer:

Protecting the colony from attack

Explanation:

This question is simply asking you to recall details and interpret certain words. All the relevant information is contained in the first few lines of the passage: “The workers appear to perform a never-ending round of duties. They build the nests, make the roads, attend to the wants of the young, train up the latter in the ways of ant existence, wait on the sovereigns of the nest, and like diplomatic courtiers, duly arrange for the royal marriages of the future.” Even regardless of this, it is clear from the rest of the passage that the responsibility of protecting the colony from attack falls with the soldier ants.

Example Question #1 : Comparing And Contrasting In Science Passages

Adapted from “Comets” by Camille Flammarion in Wonders of Earth, Sea, and Sky (1902, ed. Edward Singleton Holden)

The history of a comet would be an instructive episode of the great history of the heavens. In it could be brought together the description of the progressive movement of human thought, as well as the astronomical theory of these extraordinary bodies. Let us take, for example, one of the most memorable and best-known comets, and give an outline of its successive passages near the Earth. Like the planetary worlds, comets belong to the solar system, and are subject to the rule of the Star King. It is the universal law of gravitation which guides their path; solar attraction governs them, as it governs the movement of the planets and the small satellites. The chief point of difference between them and the planets is that their orbits are very elongated, and instead of being nearly circular, they take the elliptical form. In consequence of the nature of these orbits, the same comet may approach very near the sun, and afterwards travel from it to immense distances.

Thus, the period of the Comet of 1680 has been estimated at three thousand years. It approaches the sun, so as to be nearer to it than our moon is to us, whilst it recedes to a distance 853 times greater than the distance of the Earth from the sun. On the 17th of December, 1680, it was at its perihelion—that is, at its greatest proximity to the sun; it is now continuing its path beyond the Neptunian orbit. Its velocity varies according to its distance from the solar body. At its perihelion it travels thousands of leagues per minute; at its aphelion it does not pass over more than a few yards.  

Its proximity to the Sun in its passage near that body caused Newton to think that it received a heat twenty-eight thousand times greater than that we experience at the summer solstice, and that this heat being two thousand times greater than that of red-hot iron, an iron globe of the same dimensions would be fifty thousand years entirely losing its heat. Newton added that in the end, comets will approach so near the sun that they will not be able to escape the preponderance of its attraction, and that they will fall one after the other into this brilliant body, thus keeping up the heat which it perpetually pours out into space. Such is the deplorable end assigned to comets by the author of the Principia, an end which makes De la Brétonne say to Rétif: "An immense comet, already larger than Jupiter, was again increased in its path by being blended with six other dying comets. Thus displaced from its ordinary route by these slight shocks, it did not pursue its true elliptical orbit; so that the unfortunate thing was precipitated into the devouring centre of the Sun." "It is said," added he, "that the poor comet, thus burned alive, sent forth dreadful cries!"

According to the author, what is the primary difference between comets and planets?

Possible Answers:

Comets move much faster through space than planets.

Planets move in a circular orbit, whereas the orbits of comets are elongated.

Planets have been around for billions of years, comets are constantly formed and then destroyed.

Planets are much bigger than comets.

Comets are much more destructive than planets.

Correct answer:

Planets move in a circular orbit, whereas the orbits of comets are elongated.

Explanation:

Answering this question requires you to read carefully in detail. For example, you know that planets are not necessarily bigger than comets because the author talks about how a comet bigger than Jupiter once crashed into the sun. You also know that comets do not necessarily move much faster through space than planets because the author talks about the varied speeds of comets and how they can sometimes slow to a relative crawl. The correct answer is found towards the end of the first paragraph, where the author says, “The chief point of difference between [comets] and the planets is that their orbits are very elongated, and instead of being nearly circular, they take the elliptical form.” So, the orbit of planets is “nearly circular” and the orbit of comets is “very elongated,” in “the elliptical form.”

Example Question #1 : Identifying And Analyzing Supporting Ideas In Science Passages

Adapted from "Bats" by W. S. Dallas in A Book of Natural History (1902, ed. David Starr Jordan)

Like the owls, with which they share the dominion of the evening air, the bats have a perfectly noiseless flight; their activity is chiefly during the twilight, although some species are later, and in fact seem to keep up throughout the whole night. As they rest during the day, concealed usually in the most inaccessible places they can find, and are seen only upon the wing, their power of flight is their most striking peculiarity in the popular mind, and it is perhaps no great wonder that by many people, both in ancient and modern times, they have been regarded as birds. Nevertheless, their hairy bodies and leathery wings are so unlike anything that we ordinarily understand as pertaining to a bird, that opinion was apparently always divided, as to the true nature of these creatures—“a mouse with wings,” as Goldsmith called it once, according to James Boswell, is certainly a curious animal, and very difficult to classify so long as the would-be systematist has no particularly definite ideas to guide him. The likeness of the bat to a winged mouse has made itself felt in the name given to the creature in many languages, such as the “chauvesouris” of the French and the “flitter-mouse” of some parts of England, the latter being reproduced almost literally in German, Dutch, and Swedish, while the Danes called the bat a “flogenmues,” which has about the same meaning.

Why does the author believe many people have long regarded bats as birds?

Possible Answers:

Because bats lay eggs

Because bats have feathers

Because bats live in nests

Because bats can fly

Because bats live atop trees and on the roof of caves

Correct answer:

Because bats can fly

Explanation:

This is a relatively simple detail-based question. The author says, "their power of flight is their most striking peculiarity in the popular mind, and it is perhaps no great wonder that by many people, both in ancient and modern times, they have been regarded as birds.” So, it is clear that the author believes many people have considered bats to be a bird because bats can also fly.

Example Question #21 : Main Idea, Details, Opinions, And Arguments In Narrative Science Passages

Adapted from "Inhabitants of My Pool" by Arabella B. Buckley in Wonders of Earth, Sea, and Sky (1902, ed. Edward Singleton Holden)

The pool lies in a deep hollow among a group of rocks and boulders, close to the entrance of the cove, which can only be entered at low water; it does not measure more than two feet across, so that you can step over it, if you take care not to slip on the masses of green and brown seaweed growing over the rocks on its sides, as I have done many a time when collecting specimens for our saltwater aquarium. I find now the only way is to lie flat down on the rock, so that my hands and eyes are free to observe and handle, and then, bringing my eye down to the edge of the pool, to lift the seaweeds and let the sunlight enter into the chinks and crannies. In this way I can catch sight of many a small being either on the seaweed or the rocky ledges, and even creatures transparent as glass become visible by the thin outline gleaming in the sunlight. Then I pluck a piece of seaweed, or chip off a fragment of rock with a sharp-edged collecting knife, bringing away the specimen uninjured upon it, and place it carefully in its own separate bottle to be carried home alive and well.

Now though this little pool and I are old friends, I find new treasures in it almost every time I go, for it is almost as full of living things as the heavens are of stars, and the tide as it comes and goes brings many a mother there to find a safe home for her little ones, and many a waif and stray to seek shelter from the troubled life of the open ocean.

You will perhaps find it difficult to believe that in this rock-bound basin there can be millions of living creatures hidden away among the fine feathery weeds; yet so it is. Not that they are always the same. At one time it may be the home of myriads of infant crabs, not an eighth of an inch long, another of baby sea-urchins only visible to the naked eye as minute spots in the water, at another of young jelly-fish growing on their tiny stalks, and splitting off one by one as transparent bells to float away with the rising tide. Or it may be that the whelk has chosen this quiet nook to deposit her leathery eggs; or young barnacles, periwinkles, and limpets are growing up among the green and brown tangles, while the far-sailing velella and the stay-at-home sea-squirts, together with a variety of other sea-animals, find a nursery and shelter in their youth in this quiet harbor of rest.

And besides these casual visitors there are numberless creatures which have lived and multiplied there, ever since I first visited the pool. Tender red, olive-colored, and green seaweeds, stony corallines, and acorn-barnacles lining the floor, sea-anemones clinging to the sides, sponges tiny and many-colored hiding under the ledges, and limpets and mussels wedged in the cracks. These can be easily seen with the naked eye, but they are not the most numerous inhabitants; for these we must search with a magnifying glass, which will reveal to us wonderful fairy-forms, delicate crystal vases with tiny creatures in them whose transparent lashes make whirlpools in the water, living crystal bells so tiny that whole branches of them look only like a fringe of hair, jelly globes rising and falling in the water, patches of living jelly clinging to the rocky sides of the pool, and a hundred other forms, some so minute that you must examine the fine sand in which they lie under a powerful microscope before you can even guess that they are there.

Which of these statements is most clearly supported by the text?

Possible Answers:

The author has only recently begun visiting the rock pool and still does not understand it well.

The author collects specimens from the rock pool and takes them back to her house.

None of these statements are supported by the text.

The variety of the ecosystem in the pool can be attributed in part to the author’s interference.

The rock pool has a fixed ecosystem that rarely incorporates new inhabitants.

Correct answer:

The author collects specimens from the rock pool and takes them back to her house.

Explanation:

Answering this question requires you to read carefully in detail throughout the entirety of the passage. Specifically, you need to process what the author is saying when she says, “I have done many a time when collecting specimens for our salt-water aquarium" and "bringing away the specimen uninjured upon it, and place it carefully in its own separate bottle to be carried home alive and well.” This tells you that the author collects specimens from the rock pool and takes them back to her house to put into her “salt-water aquarium.” You could perhaps infer that the author affects the variety of the ecosystem, but this requires more inference than the correct answer, which is directly stated.

Example Question #121 : Science Passages

Adapted from "Inhabitants of My Pool" by Arabella B. Buckley in Wonders of Earth, Sea, and Sky (1902, ed. Edward Singleton Holden)

The pool lies in a deep hollow among a group of rocks and boulders, close to the entrance of the cove, which can only be entered at low water; it does not measure more than two feet across, so that you can step over it, if you take care not to slip on the masses of green and brown seaweed growing over the rocks on its sides, as I have done many a time when collecting specimens for our saltwater aquarium. I find now the only way is to lie flat down on the rock, so that my hands and eyes are free to observe and handle, and then, bringing my eye down to the edge of the pool, to lift the seaweeds and let the sunlight enter into the chinks and crannies. In this way I can catch sight of many a small being either on the seaweed or the rocky ledges, and even creatures transparent as glass become visible by the thin outline gleaming in the sunlight. Then I pluck a piece of seaweed, or chip off a fragment of rock with a sharp-edged collecting knife, bringing away the specimen uninjured upon it, and place it carefully in its own separate bottle to be carried home alive and well.

Now though this little pool and I are old friends, I find new treasures in it almost every time I go, for it is almost as full of living things as the heavens are of stars, and the tide as it comes and goes brings many a mother there to find a safe home for her little ones, and many a waif and stray to seek shelter from the troubled life of the open ocean.

You will perhaps find it difficult to believe that in this rock-bound basin there can be millions of living creatures hidden away among the fine feathery weeds; yet so it is. Not that they are always the same. At one time it may be the home of myriads of infant crabs, not an eighth of an inch long, another of baby sea-urchins only visible to the naked eye as minute spots in the water, at another of young jelly-fish growing on their tiny stalks, and splitting off one by one as transparent bells to float away with the rising tide. Or it may be that the whelk has chosen this quiet nook to deposit her leathery eggs; or young barnacles, periwinkles, and limpets are growing up among the green and brown tangles, while the far-sailing velella and the stay-at-home sea-squirts, together with a variety of other sea-animals, find a nursery and shelter in their youth in this quiet harbor of rest.

And besides these casual visitors there are numberless creatures which have lived and multiplied there, ever since I first visited the pool. Tender red, olive-colored, and green seaweeds, stony corallines, and acorn-barnacles lining the floor, sea-anemones clinging to the sides, sponges tiny and many-colored hiding under the ledges, and limpets and mussels wedged in the cracks. These can be easily seen with the naked eye, but they are not the most numerous inhabitants; for these we must search with a magnifying glass, which will reveal to us wonderful fairy-forms, delicate crystal vases with tiny creatures in them whose transparent lashes make whirlpools in the water, living crystal bells so tiny that whole branches of them look only like a fringe of hair, jelly globes rising and falling in the water, patches of living jelly clinging to the rocky sides of the pool, and a hundred other forms, some so minute that you must examine the fine sand in which they lie under a powerful microscope before you can even guess that they are there.

Which of these is not a reason the author gives for why the rock pool contains such a changing and extensive ecosystem?

Possible Answers:

It is exposed to regular sunlight.

The tides regularly bring in new creatures.

It provides a safe haven for creatures threatened in the open ocean.

It is a convenient place for small sea creatures to lay their eggs and protect their young.

All of these are reasons given by the author.

Correct answer:

It is exposed to regular sunlight.

Explanation:

This question is perhaps a little difficult. You might be tempted to pick the answer that begins with “All of these are reasons“ because you probably know that the exposure to regular sunlight is a very important factor in the maintenance of such a large ecosystem. However, the author does not explicitly state this. Regarding sunlight, she says, “let the sunlight enter into the chinks and crannies. In this way I can catch sight of many a small being either on the seaweed or the rocky ledges, and even creatures transparent as glass become visible by the thin outline gleaming in the sunlight.” She talks about the way sunlight allows her to see various sea creatures, but she does not mention how sunlight affects the ecosystem.

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