Now, it is likely that you will think that the sentence is describing Richard's lack of sleep as being "exhausting" or even "demanding;" however, the sentence really is not addressing this aspect of his lack of sleep. Instead, it is concerned to say that it was indeed a harm to his health, even though he did not think it would be. Thus, the best option is "detrimental," meaning harmful.

The key point in this sentence is that Nicholas's new computer did not seem to add any benefit. It seemed to fill the same role as that of his original laptop. It was therefore superfluous. We do not know much about its cost, so "expensive" does not work well. The options "extreme" and "overwhelming" are not really justified by the subordinate clause which describes his family's reaction. Thus, the best option is "redundant," which means superfluous and not creating much additional benefit. A redundant thing is a kind of duplicate that really doesn't change matters—the first thing would be enough.

The key thing to note about Sebastian is that he had high expectations of "his workers." Now, this might have been tedious and bewildering for some and even hateful for others. Still, high expectations are not necessarily any of these things. All that we know is that he was demanding with such expectations, and "exacting" means just this.

The implication of this sentence is that children "during a growth spurt" will eat heartily and in great quantities. When someone has a voracious appetite, he or she has a seemingly "endless appetite." Thus, it is appropriate to say that such children's eating can be described by the adverb "voraciously."

If the speaker of this sentence hit a parked car with his bike it would make sense that he would want to offer his most sincere and abundant apology. The best answer choice here then is "profuse" which means copious and abundant. To provide further help, "docile" means calm; "laudable" means deserving of praise; "morose" means very sad and serious; "garrulous" means talkative. 

From the context of the sentence it is clear that the boy did not listen to his mother and did give money to the homeless man. Giving selflessly to others is an example of "altruism" so this is the correct answer. "Altruistic" means selfless, giving. To provide further help, "ebullient" means enthusiastic; "virulent" means strong and powerful. 

Someone who is able to predict the future is called "clairvoyant." To provide further help, "serendipitous" means owed to good fortune; "antagonistic" means combative, seeking conflict; "contrarian" means someone who disagrees with others often and deliberately; "abstruse" means hard to understand. 

You are told that the teacher was beloved by her students so when she retired it makes sense that she would be given a certificate that praises her or attests to how good of a teacher she was. The correct answer is therefore "meritorious." "Meritorious" means deserving of praise. To provide further help, "pedestrian" means mediocre; "resilient" means tough, able to deal with setbacks; "blasphemous" means irreverent, using disrespectful language particularly towards God; "blithe" means casual, indifferent.

You are provided very little information in this problem. All you know is that the subject stood up, meaning he was previously lying down. This clue should lead you to the correct answer "recumbent" which means lying flat, lying down. To provide further help, "contrite" means remorseful, feeling sorry for something done; "nominal" means not important, insignificant; "disconsolate" means hopeless; "assiduous" means hard working.

Based on the context of this sentence the underlined word must mean something like bad or average - if the athlete performed well she would not want to change coaches. So, the correct answer is "pedestrian." "Pedestrian" means dull, uninspired, mediocre. To provide further help, "comely" means cute; "luminary" means notable, an important person (and is also a noun, not an adjective, so it cannot be correct here); "posh" means wealthy and refined; , "formidable" means daunting.