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

Tourism has certainly__________ an important factor in the development of many countries.

A. to become

B. become

C. became

D. becoming

Đáp án
B. become

Câu hỏi thuộc Bài tập:

E9- TĐ- Test for Unit 8