Correct Answer: A

Rationale: The correct answer is A. A compound sentence consists of two independent clauses joined by a conjunction or a semicolon. In sentence A, 'The sky is clear' and 'the stars are bright' are two independent clauses joined by the conjunction 'and.'<br>Choice B is a complex sentence as it has a dependent clause ('Although it was late') and an independent clause ('he stayed up').<br>Choice C is a simple sentence with only one subject and one verb.<br>Choice D is a complex sentence with a dependent clause ('While she reads') and an independent clause ('she listens to music').

Correct Answer: B

Rationale: Choice B is the correct answer because it serves as a transition sentence in the paragraph about the Silk Road. It shifts the focus from Chinese silk being a major trade item to the introduction of other important trade items that had a significant impact on the world. This transition indicates a change in the topic being discussed within the paragraph. Choices A, C, and D do not serve as transition sentences. Choice A simply introduces the origin of the Silk Road's name, choice C provides additional information about the network without transitioning to a new topic, and choice D gives a general description of the Silk Road without transitioning to a different aspect of the trade routes.

Correct Answer: D

Rationale: The correct answer is D: 'Sleepwalker'. The word 'somnambulist' refers to a sleepwalker, as indicated by the context of waking up outside in pajamas in the middle of the night. A sleepwalker is someone who walks while asleep, and this matches the situation described in the sentence. Choices A, B, and C are incorrect because they do not align with the behavior of walking during sleep, which is characteristic of a somnambulist/sleepwalker.

Correct Answer: A

Rationale: The correct answer is A: 'To go around.' Circumvent means to find a way around an obstacle or to avoid something by cleverness or deception. Choice B, 'To go under,' is incorrect as circumvent does not involve going under something. Choice C, 'To come near,' is incorrect as circumvent does not mean to approach or get close to something. Choice D, 'To come through,' is incorrect as circumvent does not involve passing through something.

Correct Answer: A

Rationale: The correct answer is A: 'Performed by one person.' 'Unilateral' means something done by one person or group without the agreement of another. Choice B is incorrect as it suggests the opposite of what 'unilateral' means. Choice C is incorrect as it does not capture the essence of 'unilateral.' Choice D is incorrect as it is not directly related to the definition of 'unilateral.'