______ before bed, cellphones can result in a restless night.
| A．To use | B．Using | C．Used | D．Having used |
He said that very clearly so that nobody was in any ______ about what he meant.
| A．doubt | B．case |
| C．question | D．wonder |
In my opinion, life in the twenty-first century is much easier than ______ .
| A．that used to be | B．it is used to be |
| C．it was used to | D．it used to be |
It is often ______ that human beings are naturally equipped to speak.
| A．said | B．to say |
| C．saying | D．being said |
Please don't ______ him. He is quite ______ about his girlfriend's words right now.
| A．disturb; disturbing | B．disturbed; disturbing |
| C．disturb; disturbed | D．disturbing; disturbed |
The drug did not ______ his health. In fact，it seemed to have no ______ at all.
| A．effect; effect | B．effect; affect |
| C．affect; effect | D．affect; affect |