Correct Answer: B

Rationale: The word 'envelope' is used incorrectly in the sentence. The correct word should be 'folder,' as mentioned in the original sentence. An envelope is a flat paper container for a letter or documents, while a folder is a folded cover for papers or documents. 'Give,' 'whoever,' and 'replies' are all used appropriately in the sentence, so they are not the incorrect words.

Correct Answer: C

Rationale: In the context of the sentence, the word 'then' is used incorrectly. The correct word that should be used is 'than,' which is used to make comparisons. The sentence should read, 'Nothing can be more delightful than a late-night swim in the reservoir.' The other choices 'Nothing,' 'delightful,' and 'reservoir' are spelled correctly and are contextually appropriate in the sentence.

Correct Answer: D

Rationale: The correct answer is 'D: broken.' In this sentence, the word 'broken' is the past participle form of the verb 'break' and is needed to complete the present perfect tense. The correct sentence should be 'The girls have apparently broken curfew at least twice this week.' Choices A, B, and C do not fit grammatically in the sentence because 'broke' is the simple past tense, 'break' is the base form, and 'breaking' is the present participle, whereas the sentence requires the past participle 'broken' for the present perfect tense.

Correct Answer: C

Rationale: The word 'otherwise' is used to indicate that although the patients are resting comfortably, under different circumstances, bed checks should still be done every half hour. This maintains the correct logic and flow of the sentence, making it grammatically correct. Choice A, 'despite,' would imply a contrasting situation that is not the intended meaning in this context. Choice B, 'however,' also implies a contrast rather than the intended conditional relationship. Choice D, 'afterward,' indicates a time sequence that does not fit the context of the sentence.

Correct Answer: A

Rationale: In this sentence, the word 'flock' is singular, so the pronoun that follows should also be singular. Therefore, the correct choice is 'its,' which refers back to the singular noun 'flock.' Choice B ('their') is incorrect because it is a plural pronoun and does not agree in number with the singular noun 'flock.' Choices C ('it's') and D ('they're') are both incorrect contractions that do not fit grammatically in this context.