Correct Answer: B

Rationale: The correct answer is B: 'Vague.' Nebulous means something that is vague or unclear. Choices A, C, and D are incorrect because nebulous is the opposite of clear, distinct, and complex. Nebulous refers to something lacking definite form or limits, making it difficult to understand or perceive clearly.

Correct Answer: A

Rationale: The correct answer is A: 'The homework was completed by the student.' This sentence is in the passive voice because the subject (homework) is being acted upon by the student. In passive voice constructions, the subject receives the action rather than performing it. Choices B, C, and D are in active voice where the subject performs the action. In choice B, 'The student completed the homework,' the subject (student) is the one performing the action of completing the homework.

Correct Answer: B

Rationale: The correct answer is 'B: Outdated.' Obsolete refers to something that is outdated or no longer in use. 'Innovative' (choice A) means introducing new ideas or methods; 'Effective' (choice C) means successful in producing a desired result; 'Advanced' (choice D) means far on or ahead in development or progress. Therefore, 'Outdated' is the most appropriate antonym for 'Obsolete.'

Correct Answer: B

Rationale: The correct meaning of the word 'Augment' is 'to add to something.' Therefore, choice B, 'Add to,' is the correct answer. Choices A, C, and D are incorrect because they all suggest actions that involve reducing or decreasing something, which is the opposite of augmenting.

Correct Answer: B

Rationale: The correct answer is B: 'Produced within the body.' Endogenous refers to substances or processes that originate or are produced within an organism or system. Choices A, C, and D are incorrect. Choice A, 'Produced outside the body,' is the opposite of endogenous. Choice C, 'Taken from an external source,' describes exogenous rather than endogenous. Choice D, 'Linked to environmental factors,' is not a direct definition of endogenous.