—I plan to pay a visit to Peter this Sunday．
—I agree. You know, he ________come to see us on Sundays when we were in USA.．
A. might B. would C. should D. could
__________ in 1636, Harvard is one of the most famous universities in the United States.
| A．Being founded |
| B．It was founded |
| C．Founded |
| D．Founding |
When __________, the museum will be open to the public next year.
| A．completed |
| B．completing |
| C．being completed |
| D．to be completed |
The research is so designed that once __________ nothing can be done to change it.
| A．begins |
| B．having begun |
| C．beginning |
| D．begun |
__________ more attention, the trees could have grown better.
| A．Given |
| B．To give |
| C．Giving |
| D．Having given |
__________ many times, he finally understood it.
| A．Told |
| B．Telling |
| C．Having told |
| D．Having been told |