Correct Answer: D

Rationale: In the sentence, 'Could Kendra manage to carry both Kendra's books and yours?', the possessive pronoun 'hers' is the best substitution for the underlined words. The use of 'hers' correctly indicates possession by Kendra, making it the most appropriate word choice to replace 'Kendra's books'. Choice A, 'her', is incorrect as it refers to the possessive form of a singular female noun, not being possessive of 'Kendra'. Choice B, 'his', is incorrect as it is the possessive pronoun for a singular male noun, not suitable for replacing 'Kendra's books'. Choice C, 'she's', is incorrect as it is a contraction for 'she is', which does not fit the possessive context needed in the sentence.

Correct Answer: B

Rationale: The correct answer is 'itself.' The sentence is referring to the centrifuge, which is an object, not a person. Therefore, the word 'itself' is used to indicate that the centrifuge cannot run on its own; it requires constant attention. Choices A, C, and D are incorrect because they refer to a person or people, which is not suitable in the context of the sentence.

Correct Answer: B

Rationale: The correct phrase to use with 'surprised' in this sentence is 'to learn.' In this context, 'to learn' functions as an infinitive to indicate the purpose or reason for the surprise. 'Learning' (Choice A) is incorrect as it doesn't serve as an infinitive in this sentence. 'Of learning' (Choice C) is incorrect as it doesn't provide the correct structure needed in the sentence. 'Have learned' (Choice D) is incorrect because the verb tense does not match the context of the sentence.

Correct Answer: C

Rationale: The word 'deserve' should be used instead of 'deserves' to match the plural subject 'few'. The subject 'few' is plural, so the verb should also be plural. Therefore, the correct sentence should be 'but only a few deserve their degrees.' Choices A, B, and D are used correctly in the sentence and do not need any changes.

Correct Answer: D

Rationale: The word 'manage' is misspelled as 'menage' in the sentence. The correct spelling of the word is 'manage.' Therefore, the correct answer is 'D: manage.' Choices A, B, and C are all spelled correctly in the context of the sentence.