－Mary, how did your Math test go?
－I had thought I _________, but in fact I came in the top 10% in my class.
| A．should have failed | B．couldn’t have failed |
| C．might have failed | D．shouldn’t have failed |
The new discovery is of ________.
| A．great significance | B．very significance |
| C．great significant | D．very importance |
Once _____ , the machine will keep running.
| A．start | B．started | C．to start | D．starting |
____ in thought, he almost ran into the car in front him.
| A．Losing | B．Having lost | C．Lost | D．To lose |
— Good morning, can I help you?
— I’d like to have this watch _______.
| A．fixed | B．to be fixed | C．to fix | D．fixing |
Look at the trouble we’re in. If only we _____ our teacher’s advice.
A. had taken B would have taken C. took D. have taken