See the flag on top of the building ? That was ___ we did this morning .
A when B. which C. where D. what
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 ____ .
| A．mustn’t be | B．may not be |
| C．can’t be | D．won’t be |
The price of the flat now is ____ that last year.
| A．as twice high as | B．twice more expensive than |
| C．as high as twice | D．twice the amount of |
— Did you watch the football match last night?
— Yes, that’s a most close one, and eventually neither could defeat ____.
| A．both | B．the other | C．another | D．each |
They chatted ____ coffee about their experience as volunteers during the charity.
| A．over | B．on | C．to | D．with |
| A．couldn't see | B．shouldn't have seen |
| C．mustn't have seen | D．can't have seen |