The pressure _____ causes Americans to be energetic, but it also puts them under a constant emotional strain (过度紧张).
| A．to compete | B．competing |
| C．to be competed | D．having competed |
He put in a special _____ for an extra day's holiday so that he could attend his daughter's wedding.
| A．request | B．demand | C．inquiry | D．proposal |
It was decided to _____ the search when there was no hope of finding the missing girl alive.
| A．call off | B．take up | C．keep off | D．ring up |
The Prime Minister refused to comment on the rumor that he had planned to _____.
| A．discharge | B．dismiss | C．resign | D．resume |
Professor Jordon is well known for his _____ into the habits of the common housefly.
| A．examination | B．introduction |
| C．research | D．expression |
I support your decision, but I should also make it clear that I am not going to be _____ to it.
| A．connected | B．fastened | C．bound | D．stuck |