So far no life has been found outside the earth, but while some scientists are actively searching for living things in outer space, others firmly believe there ______.
#87593
A
ustn’t be
B
ay not be
C
an’t be
D
on’t be
推荐题目
You _______ pay too much attention to your reading skill, as it is so important.
#88174
A
cannot
B
shouldn’t
C
mustn’t
D
needn’t
------These grapes look really beautiful. ------They _________! See the price, 3.99dollars a pound. Very expensive, aren’t they?
#88186
A
would
B
should
C
might
D
could
---Is there any flight to Tokyo today ?---I think there __, for the weather is too bad.
#89837
A
mustn’t be
B
mightn’t be
C
needn’t be
D
can’t be
It’s still early, you _____.
#90217
A
mustn’t hurry
B
wouldn’t hurry
C
may not hurry
D
don’t have to hurry
Look at the mess the boys made! You _______ have taught them how to behave themselves.
#87866
A
must
B
may
C
can
D
should