In summer milk will quickly go bad________it is put into a fridge．
A．though B．unless
C．because D．once
We felt________scared that we were afraid to go out at night．
A．such B．pretty
C．quite D．so
.Alice and Jason were sad, they were late for the meeting the heavy rain.
A.because of B.because
C.since D.as
Shanghai is one of _______ in the world .
A. more big city B. the biggest city
C. the biggest cities D. the most big city
—Do you know when back?
—I don’t know. But if he back, I will call you.
A. will he come, comes
B. he will come, comes
C. he comes, will come
I won’t go to tomorrow’s party________I am invited．
A．if B．unless C．when
