I ______ have been more than six years old when the accident happened.
| A．shouldn’t | B．couldn’t | C．mustn’t | D．needn’t |
The time is not far away ________modern communications will become widespread in China’s vast countryside.
| A．as | B．when | C．until | D．before |
____ about wild plants that they decided to make a trip to the mountain.
| A．The couple was such curious | B．So curious were the couple |
| C．How curious the couple were | D．So curious was the couple |
----What have you been ____ these days?
----Preparing for my daughter’s wedding party.
| A．up of | B．on | C．up to | D．on to |
At a rough estimate, Nigeria is ____ Great Britain.
| A．twice big as | B．as twice big as |
| C．three times the size as | D．three times the size of |
It was five o'clock in the afternoon ____they arrived at the hotel.
| A．since | B．before | C．that | D．when |