Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.

Câu hỏi

This is a difficult problem. I wish I _______ the answer.

A. know

B. knew

C. had known

D. would know

Đáp án
B. knew

Câu hỏi thuộc Bài tập:

E9- Vào 10- Đề ôn 31