Look! What you've done! You _______ more careful.
| A．may be | B．had to |
| C．should have been | D．would be |
There is plenty of rain in the southeast, there is little in the northwest.
| A．because | B．therefore |
| C．while | D．as |
Don't leave the waterwhile you brush your teeth.
| A．run | B．running |
| C．being run | D．to run |
Wearrive at six. But I'm sorry we are late.
| A．should | B．were supposed to |
| C．must | D．ought to |
Onlyto use this reading room. Students have another room on the second floor.
| A．are the teachers allowed | B．are allowed the teachers |
| C．the teachers are allowed | D．the teachers allowed |
The police will have tothe room for fingerprints.
| A．check | B．examine |
| C．clean | D．analyze |