________ advertisements are of great help, I don’t think we should entirely rely on them.
| A．Because | B．Since | C．Once | D．While |
You’d never heard of it before I told you,________?
| A．did you | B．didn’t you | C．would you | D．had you |
You all had a good time yesterday,________?
| A．hadn’t you | B．haven’t you | C．didn’t you | D．don’t you |
The Greens seldom go to the concert,________?
| A．don’t they | B．do they | C．don’t he | D．do he |
The shop doesn’t open until 11 a. m.,________ it loses a lot of business.
| A．for | B．or | C．but | D．so |
Most of the Europeans refuse to accept GM food________Americans regard it as the fruit from high tech.
| A．when | B．as | C．while | D．the moment |