30. —This wall of air is an effective answer to the problem and it ______ work.
—But it is a question to put such a wall of air around the statue.
A.may | B.must | C.should | D.Could |
推荐套卷
30. —This wall of air is an effective answer to the problem and it ______ work.
—But it is a question to put such a wall of air around the statue.
A.may | B.must | C.should | D.Could |