Correct Answer: D

Rationale: The correct answer is 'Were broken.' In this sentence, the subject 'glass in three of the windows' is plural, so the correct verb form should also be plural, which is 'were broken.' The verb 'broken' in the original sentence is in the past participle form, which is used correctly in the corrected answer choice 'D.' Choices A, B, and C are incorrect because they do not match the subject in number ('glass in three of the windows') and do not use the correct past participle form of the verb.

Correct Answer: C

Rationale: The correct answer is 'C: Had known.' In this sentence, the structure is a third conditional, which is used for unreal situations in the past. 'Had known' is the correct past perfect form that matches the conditional structure. It indicates that if they had possessed the knowledge about the bad weather in advance, they wouldn't have gone to the beach. Options A, B, and D do not correctly fit the past perfect tense required in this context. 'Know' (Option A) is present tense, 'Knew' (Option B) is simple past tense, and 'Were knowing' (Option D) is incorrect and does not convey the intended meaning of the sentence in the context of a third conditional.

Correct Answer: A

Rationale: The correct answer is 'Ask' because it maintains subject-verb agreement with 'two students,' requiring a plural verb 'ask' to match the plural subject. The other choices ('Is,' 'Was,' 'Could') do not agree with the plural subject and are thus incorrect. 'Is' is singular, 'Was' is the past tense form, and 'Could' indicates a possibility but does not fit the context of the sentence.

Correct Answer: C

Rationale: 'Carried' is correct because 'should never be' requires the past participle form of the verb 'carry' to complete the sentence properly. The sentence is in the passive voice, indicating that the action is being done to the scissors, not by them. Choices A, B, and D are incorrect as they do not form the correct past participle form needed in this context.

Correct Answer: C

Rationale: The correct answer is 'Was elected' as it is the passive voice construction needed in this context. The sentence is referring to an action that happened to John F. Kennedy (being elected president), so the passive voice 'was elected' is the appropriate form to use in this sentence. Choice A, 'Elected,' is incorrect because it is the active voice and does not fit the sentence structure. Choice B, 'Was electing,' is incorrect as it is the continuous form of the verb, which is not suitable in this sentence. Choice D, 'Had elected,' is incorrect because it implies a past perfect tense which is not required in this context.