Scientists say it may be five or six years _____ it is possible to test this medicine on human patients.
| A．since | B．after | C．before | D．when |
The teacher asked a very difficult question. It was Ted who finally ____ a good answer.
| A．came up with | B．kept up with |
| C．came up | D．caught up with |
Americans and Canadians can understand each other ___ they don’t speak the same kind of English.
| A．now that | B．even if | C．as if | D．only if |
It was the second time that I the film.
| A．have seen | B．saw | C．had seen | D．see |
He asked me ________ with me.
| A．what the matter is | B．what the mater was |
| C．what’s the matter | D．what was the matter |
American English has so many _________ because the American people have come from all over the world.
| A．grammar | B．vocabulary |
| C．pronunciations | D．dialects |