giải nhanh giúp mk vs ạ cảm ơn mn

21. The correct answer is C. "The woman who son is excellent in maths lives next door to us." The sentence structure is incorrect because it should be "the woman whose son is excellent..." The word "whose" indicates possession, meaning the son belongs to the woman.

22. The sentence "Mumps are a very common disease which usually affects children." is also incorrect. The correct answer is C. "which," because in this context, "that" is preferred to introduce a defining relative clause, while "which" is typically used for non-defining clauses.

Other sentences:
20. "John: “What’s the matter?” - Tom: “Everything is fine. How about you?”" The correct answer is A, as it is the most natural response to a greeting asking if everything is alright.

19. The correct answer is C. "Harrison's greatest attribute is his ability to work under pressure." Using "under" emphasizes the context in which Harrison performs optimally, which is essential in work-related discussions.