We are needed to find a way we can think of as soon as possible________the pollution.
| A．to prevent |
| B．preventing |
| C．prevented |
| D．prevent |
Investigators are still trying to determine the __________ of the accident.
| A．cause | B．problem | C．reason | D．puzzle |
The collapse of the World Trade Center has put US economy in a difficult __________.
| A．occasion | B．case | C．situation | D．background |
What gave you the __________ of using a male actor for the part?
| A．idea | B．opinion | C．mind | D．thought |
I’m not sure what I would do if I were in your __________.
| A．condition | B．position | C．location | D．environment |
Bell’s feeling at last found __________ in tears.
| A．way | B．expression | C．answer | D．explanation |