When people cut down big trees, new trees should be planted. ,they will have no trees to cut down in the future.
| A．If not | B．If so | C．If no so | D．If don’t |
Please do me a favor-__________ my friend Mr. Smith to Youth Theater at 7 ： 30 tonight.
| A．to invite |
| B．inviting |
| C．invite |
| D．invited |
If you have a job，__________ yourself to it and finally you'll succeed.
| A．do devote |
| B．don't devote |
| C．devoting |
| D．not devoting |
-Do you think you could do without help?
-__________. This is not the first time for me.
| A．Take care |
| B．Hurry up |
| C．Not exactly |
| D．Don't worry |
Find ways to praise your children often，__________ you'll find they will open their hearts to you.
| A．till |
| B．or |
| C．and |
| D．but |
__________ at the door before you enter my room, please.
| A．Knock |
| B．Knocking |
| C．Knocked |
| D．To knock |