---What do you think of the film?
---Cool! Never before _____ a better one.
| A．had I seen | B．I have seen | C．have I seen | D．I had seen |
We cannot figure out ____quite a number of insects, birds, and animals are dying out.
| A．that | B．as | C．why | D．when |
We have been told that under no circumstances_______ the office telephone for personal affairs.
| A．may we use | B．we can use | C．we could use | D．did we use |
It was quite a serious accident, _____caused by careless driving.
| A．which I think was | B．I think which was |
| C．which I think it was | D．I think which it was |