The government of the United States began at once to investigate the case ______ a lot of students were killed.
| A．that | B．when | C．where | D．why |
—What are you doing this Saturday?
—I’m not sure，but I________go to the Rolling Stones concert.
| A．must | B．would |
| C．should | D．might |
No one ________be more generous; he has a heart of gold.
| A．could | B．must |
| C．dare | D．need |
—You needn’ t take an umbrella.It isn’t going to rain.
—Well，I don’t know.It________do.
| A．might | B．need |
| C．would | D．should |
Since nobody gave him any help，he________have done the research on his own.
| A．can | B．must |
| C．would | D．need |
－I'm afraid that I couldn't pass the examination.
－As a student，you need to believe in yourself________you have the ability to achieve any________goal.
| A．knowing；to be set | B．knowing；set | C．known；setting | D．known；to be set |