Circle the letter A, B, C, or D to indicate the correct answer to each of the following questions.

Câu hỏi

Scientists ___________ new sources to protect the environment.

A. are developing

B. develop

C. developing

D. will developing

Đáp án
A. are developing

Câu hỏi thuộc Bài tập:

E7- GS- Thi cuối kỳ 2- Test 1