Correct Answer: D

Rationale: The sentence is in the past tense, indicating that the action occurred before the present moment. 'Began' is the correct past tense form of the verb 'begin' in this context. It shows that Stan started reviewing his class notes in the past. Choice A ('begins') is incorrect as it represents present tense. Choice B ('begun') is incorrect as it is the past participle form and does not fit the sentence structure. Choice C ('begin') is incorrect as it is the base form of the verb and not appropriate for the past tense context of the sentence.

Correct Answer: D

Rationale: In this sentence, 'Our' is the possessive pronoun that correctly indicates possession, making the sentence grammatically correct. The sentence implies that the screaming belonged to a group that includes the shopkeeper. Therefore, 'Our' is the appropriate choice. The other options ('We,' 'They,' 'Them') are incorrect as they do not convey possession as required in the sentence.

Correct Answer: A

Rationale: The correct answer is 'Is.' In this sentence, the subject 'picking up groceries' is singular, so it should be followed by the singular form of the verb 'to be,' which is 'is.' The verb should agree with the subject in number. 'Am' is incorrect as it is the first person singular form, 'Is it' creates an unnecessary question structure, and 'Are' is plural, not matching the singular subject. Therefore, 'Is' is needed to make the sentence grammatically correct.

Correct Answer: C

Rationale: The word 'their' is used incorrectly in the sentence because it is a plural pronoun while 'Whoever' is singular. In this case, 'his or her' should be used instead of 'their' to maintain subject-verb agreement. The other choices 'Whoever,' 'wrote,' and 'name' are used correctly in the sentence.

Correct Answer: B

Rationale: 'Presents' is the correct choice here. The sentence requires a verb that indicates the condition appearing with a symptom. In medical terminology, when a condition 'presents' with a symptom, it means that the symptom is a noticeable feature or indication of the condition. Therefore, 'presents' is the appropriate verb to describe how the condition manifests itself with vertigo. The other options do not fit the grammatical structure of the sentence.