问题

We _______ talk loudly when we see the sign “ Be quiet ”on the right.
A:must
B:mustn’t
C:need
D:needn’t
B:mustn’t
C:need
D:needn’t
正确答案是:
同类题型
My parents will buy a piano for me if I _____ good grades in the tests.
I am going to take the entrance examination of Fudan University. —_________________
You look so happy. What happened?—I have just got an “A” in P.E. test.
I ________ when the UFO landed.
Can I help you?—Yes, I bought this radio here yesterday, but it _____________.