They have arrived at lunchtime, but their flight was delayed.
| A．will | B．can | C．must | D．should |
We must do whatever we can to ______the river from being polluted any more.
| A．separate | B．keep | C．prevent | D．guard |
We should try our best to___________ those people after the disaster.
| A．break out | B．come on | C．bring up | D．cheer up |
— I’d like to take a week holiday.
— ________, we are too busy.
| A．Don’t worry | B．Forget it | C．Don’t mention it | D．Pardon me |
---Are you going to attend the meeting _____ next Saturday?
---I won’t unless invited.
| A．being held | B．held | C．will be held | D．to be held |
________ excited Geoff Marcy most was ________ there were planets in other solar system where life might exist.
| A．It; if | B．That; whether | C．What; whether | D．What; that |