Trees can stop the sand _____ towards the rich farmland in the south.
| A．to moving | B．to move | C．from moving | D．moves |
Unless it________next week，we________to Mountain Tai．
| A．rains；go |
| B．will rain；will go |
| C．rains；will go |
| D．will rain；go |
As soon as she________in Beijing tomorrow，she________you·
| A．arrives；calls |
| B．will arrive；will call |
| C．will arrive；calls |
| D．arrives；will call |
As students，we should try________hard from now on．
| A．study |
| B．to study |
| C．studying |
| D．to studying |
—________have you been married？
—For twenty years．
| A．How far |
| B．How often |
| C．How long |
| D．How soon |
—We’ll visit the Summer Palace________there is a heavy rain tomorrow．
—OK！Boating on the lake must be great fun．
| A．unless |
| B．since |
| C．as soon as |
| D．if |