8. Answer: A. than

Explanation: In English grammar, the structure "No sooner...than" is used to describe two actions happening almost simultaneously.
Correct Sentence: No sooner had we started the picnic than the rain began pouring down!
Dịch: Vừa mới bắt đầu buổi dã ngoại thì trời đổ mưa.

23. Answer: Had the police found out, I would have been in trouble.

Explanation: This is an inversion in conditional sentences. The "if" clause is rewritten by moving the auxiliary verb (had) to the beginning.
Dịch: Nếu cảnh sát phát hiện ra, tôi đã gặp rắc rối.

10. Answer: B. do snakes

Explanation: The structure "Hardly + do/does + subject + verb" is used for emphasis in formal English.
Correct Sentence: Hardly do snakes attack people.
Dịch: Rắn hầu như không tấn công con người.

42. Answer: No longer do women in developed countries bear many children.

Explanation: The sentence uses inversion with "No longer" at the beginning for emphasis.
Dịch: Phụ nữ ở các nước phát triển không còn sinh nhiều con nữa.

41. Answer: No longer do women nowadays depend on their husband.

Explanation: The inversion structure is used to emphasize the statement with "No longer."
Dịch: Phụ nữ ngày nay không còn phụ thuộc vào chồng nữa.

5. Answer: Not until he received the offer of promotion in writing did John celebrate.

Explanation: The sentence uses the inversion with "Not until" to emphasize the timing of John's celebration.
Dịch: Chỉ đến khi nhận được lời mời thăng chức bằng văn bản, John mới ăn mừng.

2. Answer: At no time did he suspect that she was a witch.

Explanation: The phrase "At no time" requires inversion, placing "did" before the subject.
Dịch: Không lúc nào anh ta nghi ngờ cô ấy là phù thủy.