17. b. We ought to submit our assignment tomorrow.
S+ought+to-infinitive+_________.
18. d. We can hardly understand him because of his accent.
Because of+N/cụm N
19. c. After he retires, his eldest son will take over a business.
after: sau một việc, sẽ làm việc gì tiếp.
20. c. The patient recovered more rapidly than expected.
So sánh hơn với trạng từ/tính từ dài : S+be/V+more+adv/adj than _____.