Loulan, once a small, wealthy commercial city, is believed by many people___________over gradually by sandstorms from AD 200 to AD 500.
| A．covered | B．was covered | C．to be covered | D．to have been covered |
It suddenly __________ to the detective that the millionaire was probably murdered by his own daughter.
| A．happened | B．occurred |
| C．thought | D．took place |
It suddenly __________ to me that they went there by bike.
| A．happened | B．occurred |
| C．struck | D．appeared |
By hiking, people can __________ nature and enjoy a new kind of life.
| A．close to | B．close to the |
| C．get close to | D．get close to the |
-How did you find the rock music concert last night?
-__________.
| A．I went there by bike | B．I'll do my best |
| C．It was fascinating | D．You are absolutely right |
There were only __________ as ten years ago on the hill.
| A．as one third trees | B．as a third many trees |
| C．one third trees as many | D．a third as many trees |