The root "agr­-" means having to do with farming or rural life, so it makes sense that "agriculture" and "farming" are synonyms. To solve this analogy, you need to pick out the answer choice that is a synonym of "horticulture." "Horticulture" is derived from the Latin "hortus," meaning garden, and is a synonym of "gardening." So, "gardening" is the correct answer.

"Marriage" is an institution that is ended by "divorce." To solve this analogy, you have to determine which of these words describes the ending of a "contract." A "contract" is a binding agreement between two parties. When a "contract" is ended, it is said to be "terminated." It may have helped you arrive at this answer if you considered that the prefix "term-" means boundary, ending. To provide further, help, an "accord" is an agreement; "litigation" is the process of suing someone; an "anniversary" is a yearly rememberance of a specific event on a specific date, such as a birthday; "slander" is the act of writing untruthful statements about someone with the intent of negatively affecting their reputation. 

“Terrestrial” is an adjective that means having to do with the earth, so we need to pick out a noun that conveys what the adjective “celestial” refers to. “Celestial” means having to do with sky, heaven, or outer space, so while all of the answer choices describe places or land features, “celestial” refers to something that has to do with "outer space" just as “terrestrial” refers to something that has to do with the earth. So, “outer space” is the correct answer.

An octopus has eight legs, as you might be able to infer because the word "octopus" contains the prefix "octo-" at the beginning of the word. "Octo-" means eight, and appears in other words like "octagon" (an eight-sided shape). To solve this analogy, if you don't know how many legs a centipede has, you can still arrive at the correct answer by using the prefix "cent-" as a clue to infer this information. "Cent-" means one hundred and appears in other words like "centimeter" (a unit of measurement that is one-hundredth of a meter) and "century" (a span of time of one hundred consecutive years).

A nine-sided shape is called a "nonagon," and an eight-sided shape is called an "octagon." The prefix "non-" suggests that the word will have to do with the number nine. Likewise, the prefix "oct-" suggests that the word will have to do with the number eight. (For an example of this, just think of how an "octopus" has eight legs!)

“Tertiary” is an adjective that means third, so we need to pick out an answer choice that is synonymous with “quaternary.” While all of the answer choices might look like potentially correct answers, “quaternary” is an adjective that means fourth, so “fourth” is the correct answer. You can also use prefixes as context clues to help you solve this quesiton: "tertius" is Latin for third and has influenced the prefix "tri-," while "quattuor" is Latin for fourth and has influenced English words like "quad" and "quarter."

"Microeconomics" is the study of economics on a small scale, and "macroeconomics" is the study of economics on a large scale, so the correct answer is “large.” To solve this analogy, it is important to be aware of the meaning of the prefixes "micro-" and "macro-". ­"Micro-" means small and "macro-" means big.

A triangle is a three-sided shape, which you can infer because the prefix "tri-" means three. So, to solve this analogy, you have to determine how many sides a pentagon has. The prefix "penta-" means five, so the correct answer is “five.”

The prefix ­"terra-" means related to the Earth and the prefix "celes-" means related to heaven, the sky, or outer space. As “terrestrial” is to Earth, so “celestial” is to space, so "space" is the correct answer. For clarification, “terrestrial” means of this Earth or observed on this Earth, and “celestial” means of space or observed in space or the heavens.

If you "double" something, you increase it by two-fold. The prefix "quad-" means related to the number four, so when you quadruple something, you increase it by four-fold. So, the correct answer is "four."