I’m always ________ about what I say because careless remarks are likely to hurt others’ feelings.
| A．enthusiastic | B．curious |
| C．doubtful | D．cautious |
—Did you hear about the hero who rescued the child from the burning building?
—Yes. What do you think most people ______ if they were in a similar situation?
| A．will do | B．will have done |
| C．would do | D．would have done |
A person , when_________，can often do what is normally beyond his ability.
| A．challenged | B．challenges |
| C．challenging | D．to challenge |
Mark needs to learn Chinese ______ his company is opening a branch in Beijing.
| A．unless | B．until | C．although | D．since |
They _________ have arrived at lunchtime but their flight was delayed.
| A．will | B．can |
| C．must | D．should |
The year 1949 ________ the birth of a new country—the People’s Republic of China.
| A．found | B．watched |
| C．noticed | D．saw |