The prefix "re-" means again or back, so it makes sense that a “reaction” is a response to an action. How you behave after hearing or seeing something is your “reaction” to it. This is closest to “response.” As for the other answer choices, "reproach" can be used as a noun meaning something conveying that one is not happy with something someone else has done; a "misstep" is a step where one shouldn't step, or more generally, a mistake; a "rest" is a break, especially from physical exertion; and a "demand" is something a person or group requires before they will agree to do something.

The word "renewal" clearly is made up of two parts: (1) the prefix "re-" and (2) the base "newal." The prefix "re-" here means again, as in "repeat" and "recognize." (To "re-cognize" is to know something again—to know that person is, for example, your friend Sally, whom you know.)

A "renewal" is a making new again. It is a return to a more vibrant time or state of affairs. To "renew" wedding vows is to make them again, with the intent of living them more fully. A religious "renewal" is a return to more dedicated religious practice. Among the options provided, do not be tempted by the trick answer "return." Yes, every "renewal" could be said to be a return to the best times or to devotion. However, a "renewal" is even better said to be a "revival," which literally means "returning to life." The "-vival" portion is related to the Latin for life or to live and is found in words like "survive" and "vivacious."

The word "forecast" is something like a copy of "predict," though the words are not exactly the same. The prefix "fore-" means before or prior to. Something in the "foreground" is in the front of a picture or scene as opposed to the "background." A "forecast" is something that looks to see what will happen before it actually happens. A weather forecaster is someone who makes such predictions about the weather.

The word "predict" has the prefix "pre-," which also means before. The "-dict" portion of the word comes from roots meaning to speak or say. To "pre-dict" is to "say before"—that is, to speak about an event before it occurs. Thus, it is a good synonym for "forecast." Indeed, it is basically its definition!

The word "preamble" is composed of two parts. The prefix "pre-" means before—as you likely know from words like "precede" and, of course, "prefix." The "-amble" portion is a bit rarer. It comes from the Latin for to walk and is found in words like "amble" and "ambulatory." (The latter means able to walk.) The "preamble" of a document is the beginning portion—the part that "walks before" the rest of the document. It is the "introduction" to the document. It does not necessarily outline or explain the document, though it can. Primarily, what it means to be a "preamble" is to be an introduction or a beginning to a text.

“Lawful” means allowed or within the law so “unlawful” must mean not allowed or not within the law. “Illegal” is the closest synonym. To provide further help, “despite” means regardless of something; a “famine” is a massive scarcity of food; “malevolent” means bad-natured and “benevolent” means good-natured.

When used as a verb, "function" means work. The prefix "mal-" means bad, so if something “malfunctions,” it stops working, works incorrectly, or breaks. "Break" is thus the correct answer. As for the other answer choices, “repair” means fix; "overlook" means miss some detail when considering the bigger picture, "trace" means outline or track down; and "mechanize" means begin to use machines to do something that previously wasn't done by machines.

The prefix "over-" means excessively, so “overconfident” means excessively confident, or "arrogant." As for the other answer choices, “meek” means shy and quiet; “cantankerous” means grumpy, angry, and easily annoyed; “quaint” means old-fashioned and charming; and "rude" means disrespectful.

In order to solve this synonym problem you have to consider both the prefix and suffix of the word "omnipresent." The prefix omni- means every, all and the suffix -present means place, where. So the word "omnipresent" means everywhere, in all places. To provide further help, "greedy" means wanting more than you have/need; "fortunate" means lucky and "unfortunate" means unlucky. Notice the impact of the prefix un-. 

The prefix anti- means against. So an "antidote" is something used against poisons, used to provide a solution to poison. This is closest in meaning to "medicine." 

To solve this synonym you need to rely on your knowledge of prefixes. The prefix du- means two of, so a "duplicate" is a second copy of something. It is common to make a "duplicate" of something if it is important and you do not want to lose it, like a "duplicate" key.