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: C

Rationale: "Pondering" is another word for contemplating because it means to think about something carefully or thoroughly. Both terms imply deep reflection or consideration of a subject or idea. Therefore, "pondering" best captures the meaning of contemplating among the given choices.

Correct Answer: B

Rationale: The correct answer is B, 'Wide open'. Gaping refers to something being wide open, not partially closed (choice A), narrow (choice C), or sealed (choice D). In the context of the question, 'Gaping' describes something that is open widely.

Correct Answer: B

Rationale: The correct answer is B: 'Swift.' Precipitous is used to describe something that is steep, sheer, or done suddenly and without careful consideration. For example, a precipitous drop in the stock market. 'Slow' (Choice A), 'Gradual' (Choice C), and 'Delayed' (Choice D) do not align with the meaning of precipitous and are therefore incorrect.

Correct Answer: A

Rationale: After robbing the bank, 'the thief fled' is the correct choice as it logically follows the action of robbing a bank. The singular pronoun 'he' in choice B is not appropriate as 'the thief' is singular. Choices C and D use 'they,' which is a plural pronoun and does not agree with 'the thief,' making them grammatically incorrect.