Nothing is so easy as ________ parents to raise their expectations of their children too high.
| A．of | B．for | C．by | D．to |
If I ___ free tonight, I'll go to the cinema with you.
| A．am | B．was | C．will be | D．be |
Edison had built a chemical lab of ___ when he was very young.
| A．himself | B．him | C．itself | D．his own |
This is the only one of the books on space ___.
| A．that has been written | B．that have been written | C．which have been written | D．which has been written |
---Please help me, will you? ---_____.
| A．You’re welcome | B．Of course, I will | C．Not at all | D．It’s my pleasure |
The twins looked exactly the same.Even I couldn't ___ one from the other.
| A．speak | B．talk | C．say | D．tell |