Mr. Smith would have come to see you if it had been possible, but he __________ so busy.
| A．was | B．had been | C．has been | D．were |
The theory________by Einstein was later to prove true, but at that time few people could accept it .
| A．put out | B．put together | C．put aside | D．put forward |
Was it in 2000________he was still in middle school________this boy became an
expert at computer?
| A．when; that | B．that; where |
| C．when; where | D．that; that |
Can you think of some cases ________drivers obviously knew the traffic rules but
didn't obey them?
| A．why | B．where | C．as | D．which |
..---You haven't said one word about the design, Joe. What's your idea?
---Sorry. I________about something else.
| A．thought | B．am thinking |
| C．was thinking | D．had thought |
---Have you found your book yet?
--- No, I’m not sure where I________it?
| A．leave | B．had left | C．could have left | D．was to leave. |