The CDs are on sale！Buy one and you get ______ completely free.
| A．other | B．others | C．one | D．ones |
__________ the train arrived, some people were waiting inside the station __________ others were heading for the platform.
| A．While ； while |
| B．While ； when |
| C．When ； when |
| D．When ； while |
It was __________ fan that we couldn't hear anything.
| A．so noisy |
| B．such noisy |
| C．such a noisy |
| D．so a noisy |
Gunpowder,__________ we all know, was invented in ancient China.
| A．it |
| B．which |
| C．as |
| D．that |
Strong typhoons hit this area very __________. Normally, they form and come here between July and August every year.
| A．generally |
| B．regularly |
| C．usually |
| D．suddenly |
We all write __________, even when there's not much to say.
| A．now and then |
| B．by and by |
| C．step by step |
| D．more or less |