Correct Answer: B

Rationale: Ominous means giving the impression that something bad or unpleasant is going to happen; threatening; inauspicious. This choice is correct as it accurately reflects the meaning of the term 'Ominous.' Choices A, C, and D are incorrect because they all suggest a lack of importance, danger, or threat, which is opposite to the actual meaning of 'Ominous.'

Correct Answer: A

Rationale: A prefix is the correct answer. A prefix is a word part attached at the beginning of a word to modify its root word, changing the definition or grammatical function of the word. Examples of prefixes include "un-" in "unhappy," "re-" in "redo," and "pre-" in "preview." Choice B, "Affix," is incorrect because while a prefix is a type of affix, not all affixes are prefixes. Choice C, "Suffix," is incorrect as a suffix is a word part added at the end of a word to change its meaning. Choice D, "Vocab," is incorrect as it refers to vocabulary or words related to a particular subject rather than a word part placed before a word.

Correct Answer: B

Rationale: The correct answer is B: 'Uneven.' Asymmetric means lacking symmetry or being uneven, so the term 'Uneven' is the most appropriate synonym. 'Even' (choice A) means equal or level, which is the opposite of asymmetric. 'Identical' (choice C) means similar or the same, and 'Matching' (choice D) means corresponding or fitting together, neither of which captures the meaning of asymmetric.

Correct Answer: B

Rationale: The correct answer is B: Misgivings. Trepidation means a feeling of fear or apprehension. In this context, the student observed the procedure with a certain amount of trepidation, indicating that they were feeling uneasy or fearful. Choices A, C, and D are incorrect. Confidence (choice A) is the opposite of trepidation, as it denotes a feeling of self-assurance. Fear (choice C) is the closest synonym to trepidation, making it an attractive distractor, but it is not the correct answer. Doubt (choice D) is different from trepidation, as doubt refers to a feeling of uncertainty or lack of conviction, not necessarily fear or apprehension.

Correct Answer: D

Rationale: The sentence 'He runs fast' uses 'fast' correctly as an adverb. An adverb is used to describe a verb and in this case, 'fast' is describing how 'he runs.' Choices A, B, and C use 'fast' as an adjective, not an adverb. In choice A, 'fast' is describing the car, in choice B it is describing how the car drove, and in choice C it is describing the runner.