问题:
You _____ go and ask Tom. He _____ know the answer.
[ ]
A. must; can
B. need; can
C. can; may
D. must; may
You _____ go and ask Tom. He _____ know the answer.
B. need; can
C. can; may
D. must; may
[ ]
A. must; can B. need; can
C. can; may
D. must; may
参考答案: