Many more policeman should be sent to ________them ________some endangered animals.
| A．prevent; to hunt | B．stop; hunting | C．keep; to hunt | D．keep; hunting |
He studied hard and ____ pass the examination .
| A．could able to | B．could | C．was able to | D．ought |
The money was soon spent , so he ____ go hungry .
| A．must | B．had to | C．might | D．should |
— Would you open the window , please ?
— Yes , I ____ .
| A．will | B．would | C．do | D．can |
I''m surprised that he ____ to help me when I needed his help .
| A．should refuse | B．would have refused |
| C．should have refused to | D．may have refused |
A lion ____ only attack a human being when it is hungry .
| A．should | B．can | C．will | D．shall |