问题

no life has been found outside the earth, but while some scientists are activelysearching for living things in outer space, others firmly believe there ______.

A:mustn’t be
B:may not be
C:can’t be
D: won’t be

正确答案是：

同类题型

There is no simple answer，________is often the case in science

You know this kind of metal is ______ good quality.[ ]

My camera can be _____ to take pictures in cloudy or sunny conditions.

How much did you pay for that— I paid _____ that you paid

Are you content with her lecture— Nowhere near that It