Many people claim that they have seen UFO with their own eyes, _____ I personally doubt.
| A．that | B．which | C．when | D．where |
— Are there any flights for Hong Kong tomorrow?
— _______ Why not give a call to find it out?
| A．I’ve no idea. | B．It depends. |
| C．Why not stay longer? | D．Are you leaving? |
They urged that the library ______ open during the vacation.
| A．must be kept | B．is kept | C．would be kept | D．be kept |
The environmentalists said wild goats’______ on the vast grasslands was a good indication of the better environment.
| A．escape | B．absence | C．attendance | D．appearance |
— _______ I ask you something, if you are not busy?
—Yes, of course you _______.
| A．Should; should | B．Could; can |
| C．Could; could | D．Can; Could |
We should take good care of the elderly, as they are ______ to the sudden change of weather.
| A．sensitive | B．anxious | C．weak | D．positive |