Loulan is believed ____ by sandstorms from AD 200 to AD 400.
| A．to be gradually covered over |
| B．to have been gradually covered over |
| C．being gradually covered over |
| D．having been gradually covered over |
Books are the important records we keep___ man’s thoughts, ideas and feelings.
| A．up | B．of | C．for | D．on |
I don’t really work here; I ___ until the new secretary arrives.
| A．just help out | B．have just helped out |
| C．am just helping out | D．will just help out |
Tom sat under a tree and seeing his friend, ___ up in no time.
| A．to stand | B．standing | C．stood | D．would stand |
Being lazy ___ Peter his job.
| A．lost | B．cost | C．took | D．made |
In order not to be disturbed, I spent three days ___ up in my study.
| A．locking | B．being locked | C．to look | D．locked |