【2015·安徽】______ scientists have learned a lot about the universe, there is much we still don't know.
| A．Once | B．Since | C．Though | D．Unless |
Do remember that if you are late for the interview, you will make a bad ________.
| A．custom | B．impression | C．comment | D．manner |
He had to sell his luxury car, ________ his company was in debt.
| A．before | B．until | C．while | D．for |
---Which book do you think is the most useful to my studies?
---________, as long as you read it. In fact, they are out of date.
| A．None | B．Neither | C．Any | D．Either |
I told you the other day that Tom had agreed with your idea, ________?
| A．hadn’t he | B．didn’t he | C．did I | D．didn’t I |
---Let’s have a further talk.
---Sorry, I don’t have time. My report is due on Friday and I am in a race ________ time.
| A．over | B．in | C．on | D．against |