Correct Answer: C

Rationale: The sentence contains two independent clauses that should be separated by a semicolon or period, not a comma. The incorrect punctuation is the period after 'outside.' A period or semicolon is needed to correctly separate the two independent clauses. The comma after 'children' and 'play' are correctly used to set off non-essential participial phrases. Choice D is incorrect as there is a punctuation error in the sentence.

Correct Answer: A

Rationale: Option A correctly uses the comparative degree by comparing the quality of two movies with the word 'better.' This sentence demonstrates a comparison between two items in terms of quality, making it the correct use of the comparative degree of an adjective. Choice B uses the superlative degree ('tallest') instead of the comparative degree. Choice C uses the comparative degree correctly but with an adverb ('harder') instead of an adjective. Choice D uses the comparative degree correctly, but it compares the temperature of two coffees rather than the quality of the coffee.

Correct Answer: B

Rationale: The word 'ambiguous' implies having multiple interpretations or uncertainty, which aligns closely with 'vague,' the correct answer. 'Vague' denotes a lack of clarity or definiteness, making it the most appropriate synonym in this context. 'Precise' (Choice A) is the opposite of ambiguous, indicating exactness and clarity, so it is not the best choice. 'Definite' (Choice C) also contrasts with ambiguous as it suggests clear and certain meaning. 'Straightforward' (Choice D) implies directness and simplicity, which does not capture the essence of ambiguity.

Correct Answer: B

Rationale: The modal verb 'should' is used to imply an intention or expectation in the present or near future. Option B, 'I should be going now,' correctly conveys such a meaning, indicating the speaker's intention to leave at the current moment. Choices A, C, and D refer to past actions or future arrivals, which do not align with the appropriate usage of 'should' in this context. Therefore, option B is the only sentence that uses the modal verb 'should' correctly.

Correct Answer: C

Rationale: The determiner in the sentence is 'few.' Determiners specify the quantity or identity of a noun. In this case, 'few' indicates the number of birds present. Choice A, 'happily,' is an adverb modifying a verb or an adjective, not a determiner. Choice B, 'branches,' is a noun referring to parts of a tree, not a determiner. Choice D, 'tree,' is a noun identifying the main subject of the sentence, not a determiner.