As a noun, "blend" refers to a combination or mixture; as a verb, it means mix substances together. In any case, "mixture" is the best choice here. "Separation," or the act of moving parts away from each other, is the opposite of the correct synonym. "Progress" and "activity" are unrelated.

"Estimate" is a word that can be used as a noun or a verb, but because all of the potential answer choices are verbs, we will need to consider it as a verb. When used as a verb, "estimate" means "roughly calculate or judge the value, number, quantity, or extent of," so we need to pick out a verb that means something like "roughly calculate." So, "pinpoint" cannot be the correct answer, because when used as a verb, "pinpoint" means "find or locate exactly," which is not close in meaning to "roughly calculate." "Approximate," however, is a word that when used as a verb, means either "come close or be similar to something in quality, nature, or quantity" or "estimate or calculate (a quantity) fairly accurately." Because "approximate" is the answer choice closest in meaning to "estimate," "approximate" is the correct answer.

While "moderate" can be taken to mean an adjective meaning middling, average, or intermediate, it can also be used as a verb meaning diminish or make less. If you moderate your anger, for instance, you calm down and become less angry. Based on this definition, the correct answer is "lessen."

The word “average” is often used as an adjective meaning of middling quality in a given group. However, the word can also be used as a noun meaning mathematical mean. The correct answer to this question requires you to recognize this secondary definition, as "fantastic" is far from meaning of middling quality and can't be the correct answer.

The word "contest" has multiple meanings, one of which is a clash between two entities. (This one is pronounced "CON-test.") It can also be used as a verb ("con-TEST") that means to dispute or question a decision and ask that it be reconsidered. "Question" is thus the correct answer.

"Function" can be used as either a noun or a verb. When used as a noun, "function" means purpose; when used as a verb, "function" means work properly. So, "work" is the correct answer. “Demand” means forcefully ask or say something has to be done.

Do not confuse the word "assault" with "insult." A number of the wrong options are meant to tempt you to make this mistake. Do not fall for it! The word "assault" means to attack physically, or merely to attack. An army can assault a city, and a person can assault another person. In both cases, we are referring to some kind of physical attack. Sometimes, the word is used in a secondary sense to describe any kind of attack, like a "verbal assault." Still, the general meaning that is retained is that of attacking. Therefore, the best option among those provided is "attack."

“Prattle” is a word that can be used as a noun or a verb, but because all of the potential answer choices are verbs, we will need to consider “prattle” as a verb. When used as a verb, “prattle” means “talk at length in a foolish way,” so we need to pick out an answer choice that means something like “talk in a foolish way.” That means that “enunciate” cannot be the correct answer, because while “prattle” and “enunciate” both have to do with speech, “enunciate” means “say or pronounce clearly.” So, because “enunciate” is very distant in meaning from “prattle,” it cannot be the correct answer. “Jabber,” however, is a word that means “talk rapidly about nonsense” when used as a verb, and because “jabber” is the answer choice closest in meaning to “prattle,” “jabber” is the correct answer.

To "whirl" means to turn around in a circle quickly and repeatedly, so "spin," which also means turn around in a circle quickly and repeatedly, is the correct answer.

The word "noble" has several meanings. It can be used as a noun for a particular class of people. The "nobles" are a class of people who inherit rights from their parents, often in older countries in Europe. The "nobles" or "nobility" include dukes, barons, and other kinds of people like this. (They are sometimes called the "gentry"—sort of like "gentlemen".) They are not necessarily rulers. Therefore, we need to look for another meaning for "noble."

The word can also be used as an adjective. Among the meanings of this use of "noble," we find "honorable" or "virtuous." In these cases, we would say things like, "He was a noble man who helped all of his friends in need," or, "I gave my money to a noble cause to help the poor." Therefore, the best option is "honorable", not "politician" or "ruler." (Even "wealthy" is wrong. Someone can be a noble but not necessarily be wealthy—though the two often go together.)