2nd Grade Science
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2nd Grade Science › 2nd Grade Science
Which solution would be best and most reasonable for slowing wind and water from changing the shape of the land?
Place large umbrellas near the sides of cliffs to block the wind
There is no way to slow wind and water from changing the land, so no one should try
Bring in new sand or dirt to fill in areas that have started to wear away
Take the existing sand and add concrete to it to strengthen it
Explanation
The best and most reasonable choice for slowing wind and water from changing the shape of the land would be to bring in new sand or dirt to fill in areas that have started to wear away. Erosion is the movement of materials that have been broken down, so bringing in new sand or dirt can help slow the water and wind from changing the landform.
Which solution would be the best and most reasonable for stopping wind and water from changing the shape of the land?
Place large tarps on the sides of cliffs so the rain cannot touch the rocks.
Place large umbrellas near the sides of cliffs to block the wind.
Move all the sand away from the beach so the water cannot touch it.
Plant shrubs and trees to hold the soil together.
Explanation
The best and most reasonable way to stop wind or water for changing the shape of the land would be to plant shrubs and trees to hold the soil together. Tree roots stabilize and secure the soil helping it from being eroded. This process can help control erosion (the movement of broken-down materials), so there are fewer changes to the Earth.
The Grand Canyon is one of the United State’s best examples of erosion. Wind, rain, and the Colorado River slowly created it. These forces cut and shaped the area into what it is today. The Appalachian Mountains were a towering mountain range millions of years ago. Today their highest point is 6,684 feet tall. That same peak used to be an estimated 20,000 feet high. Erosion over time has worn the mountains down and changed them forever.
Which keywords or phrases from this text show that these events happened slowly?
"slowly," "were a towering mountain range millions of years ago," "erosion over time," and "used to be"
"one of the United State’s best examples," "cut and shaped the area," and "The Appalachian Mountains"
"The Grand Canyon is one of the United State’s best examples of erosion."
"Colorado River slowly," "towering mountain range," "highest point is 6,684 feet tall," and "20,000 feet high."
Explanation
Erosion is an extremely slow process, but the results are extraordinary. The clues in the text that let readers know this is a slow-moving process is "slowly," "were a towering mountain range millions of years ago," "erosion over time," and "used to be." These words and phrases all hint to something taking a long time to happen. Some processes on earth happen quickly, but not erosion!
Observable properties classify all of the items listed. What observable property are all of the items in "Category 2" sorted by?
Shape
Hardness
Color
Texture
Explanation
Observable properties are characteristics of an object or material that can be gathered using the five senses. When looking through each category, there is a common property that groups the items. In "Category 2," all of the items are round, so they are classified by shape.
What does the term mimic mean? Example: I can use a straw to mimic the beak of a hummingbird.
Imitate, copy, or impersonate
Extremely small or tiny
The theatrical technique of moving silently
A type of plant used to season food
Explanation
To mimic means to copy, impersonate, or imitate something or someone. If I want to mimic the behavior of a hummingbird and model a tool that is similar to its beak, the straw would be a good fit. It is a similar shape, size, and has the same function. I could copy or mimic a hummingbird's actions and collect liquid.
Animals disperse (or spread) the seeds of plants they eat. Seeds exit the digestive system of a bat while they are flying around eating fruit from different plants. When the seeds land on the ground, new plants may be formed. How can humans mimic the bat and disperse seeds?
Throw seeds out of a car window while driving
Put seeds in a pond in your yard
Eat seedless watermelon at a picnic
Roast pumpkin seeds to use in trail mix
Explanation
If humans want to develop a model for mimicking a bat dispersing seeds, the best answer choice would be to throw seeds out of a car window while driving. By tossing the seeds, it gives the change for a new plant to grow when they land in the dirt outside of the car. Humans can create models and devices to mimic animals that help keep new plants growing.
Which photo shows an Earth event that would happen quickly (in days or weeks)?
Explanation
Three of these photos depict events that happen very slowly over time. Beach erosion and the creation of canyons or rock formations take thousands, if not millions of years. The photo showing what looks like a severe tropical storm would happen quickly. The storm may build or form over a week or so, but within a day or so, the bad weather will pass. The way the storm changes the landscape may stay around longer, but the event itself happens quickly.
The Grand Canyon is one of the United State’s best examples of erosion. Wind, rain, and the Colorado River slowly created it. These forces cut and shaped the area into what it is today. The Appalachian Mountains were a towering mountain range millions of years ago. Today their highest point is 6,684 feet tall. That same peak used to be an estimated 20,000 feet high. Erosion over time has worn the mountains down and changed them forever.
What conclusion can the reader make about the formation of mountains?
It happens slowly.
It happens quickly.
It doesn't happen.
No one knows how long it takes.
Explanation
Erosion is a prolonged process, but the results are extraordinary. The clues in the text that let readers know this is a slow-moving process is "slowly," "were a towering mountain range millions of years ago," "erosion over time," and "used to be." These words and phrases all hint to something taking a long time to happen. Some processes on Earth happen quickly, but not erosion!
Which Earth event happens suddenly and can have no warning?
Explanation
The Earth event that can happen suddenly and have no warning is a volcanic eruption. Scientists can monitor volcanos but cannot predict precisely when they will erupt. It happens quickly and with little time to prepare. Islands forming, mountainside waterfalls, and canyons all take thousands, even millions of years to develop.
Which photo shows an Earth event that would happen quickly (in days or weeks)?
Explanation
Three of these photos depict events that happen very slowly over time. Beach erosion and the creation of canyons or rock formations take thousands, if not millions of years. The photo showing what looks like a severe tropical storm would happen quickly. The storm may build or form over a week or so, but within a day or so, the bad weather will pass. The way the storm changes the landscape may stay around longer, but the event itself happens quickly.