—Did he come back late last night?
—No．It was not yet eight o'clock _____ he arrived home．
| A．before | B．that | C．until | D．when |
You ________ pay too much attention to your reading skill, as it is so important.
| A．can not | B．should | C．must | D．needn't |
In such dry weather, the flowers will have to be watered if they ____________
| A．have survived | B．are to survive |
| C．would survive | D．will survive |
It is the protection for the trees___________ really matters, rather than how many trees are planted.
| A．what | B．that |
| C．不填 | D．which |
We can’t go on with the experiment because the computer_________.
| A．hasn’t been repaired | B．hasn’t repaired |
| C．is not repaired | D．hadn’t been repaired |
You can’t see the___________ now for they are having a meeting at the moment.
| A．editor-in-chiefs | B．by an hour |
| C．by hour | D．each hour |