To “succumb” means to give in, to fail to resist. For example, eventually he succumbed to her affections, or after a long and hard battle, he finally succumbed to illness.  

The word "thwart" means defeat. "Defeat" is the best choice because it is a part of the definition of "thwart." Considering the other choices, "bust" means break when used as a verb, "relinquish" means hand over unwillingly, and "scheme" means devise a plan when used as a verb or plan when used as a noun.

“Collude” means work together in some plot or scheme against someone else. The prefixes "col-," "co-," and "com-" are used to mean with or together, as seen in the words “collude,” “combat,” or “copilot.” None of the other answer choices are close in meaning to "collude": “commend” means praise, and “harangue,” “rebuke,” and “scold” all mean verbally critique.

"Ascertain" means discover or find out, so "discover" is the correct answer. None of the other answer choices are close in meaning to "ascertain": "diminish" means lessen or weaken; "emulate" means mimic or imitate; "endorse" means support; and "concur" means agree.

"Spurn" means reject with contempt, so "reject" is the correct answer. None of the other answer choices are close in meaning to "spurn": "raze" means destroy completely; "fritter" means waste or squander resources or time; "quell" means crush or put down; and "outline" means summarize or create a document that organizes the main points of an existing text or a text one plans to write.

"Succumb" means surrender or give in, so "surrender" is the correct answer. None of the other answer choices are close in meaning to "succumb": "detest" means hate passionately; "peddle" means sell by going from one location to another; "impede" means block or prevent something; "extricate" means release or remove oneself from a situation.

Imagine that one of your best friends is very angry. To calm him down, perhaps you will agree with the opinions that he is stating, even if you aren't sure whether he is right. In this case, you tried to "placate" your friend. To "placate" is to soothe or calm someone who is angry or violently frustrated, especially by conceding to his or her point(s) of view. "Appease" refers to the same process, and is the right synonym to choose here. "Frustrate" and "attack" are incorrect because they describe actions that would only make an furious person more upset, and "congratulate" conveys appreciation of an impressive feat, not pacification of an irritated person or group.

"Copy" is a verb meaning reproduce or mimic, so the answer closest in meaning to "copy" is "mimic," a verb meaning imitate. Considering the other choices,  "maintain" is a verb that means support continually, "solidify" is a verb meaning make solid, and "return" is a verb meaning to go back to.

"Flaunt" is a verb meaning display overtly in order to garner attention, so the answer choice closest in meaning to "flaunt" is "show," a verb that means present, display, or demonstrate. Considering the other options, none are close in meaning to "flaunt": "hide," when used as a verb, means conceal or conceal oneself; "ignore" means willfully refuse to notice or pay attention to; and "accuse" is a verb meaning blame.

"Suggest" is a verb that means bring up an idea as an indefinite possibility, so the answer choice closest in meaning to "suggest" is "propose," which can mean put forth an idea as a possibility. Considering the other answer choices, none are close in meaning to "suggest": "agitate" means disturb; "irritate" means annoy; and "talk" means converse by using audible words.