A recent research shows that there _____ volcanic activities on the moon and Mars. However, they no longer exist now.
| A．had been | B．has been | C．were | D．would be |
—Hello！I want to book a double room.
—Sorry.There is no double room ________.
| A．suitable | B．available |
| C．comfortable | D．cheap |
The young man comes from a(n) ________ family，who owns several companies in London and Paris.
| A．energetic | B．intelligent | C．anxious | D．wealthy |
—What was it that caused the party to be put off?
—________ the invitations.
| A．Because Tom delayed sending |
| B．Tom delayed to send |
| C．That Tom delayed sending |
| D．Tom delayed sending |
The new technology，if ________ to farming，will help increase the grain output.
| A．applying | B．to apply |
| C．applied | D．having applied |
________ this way can we smooth the difficulty we are faced with now.
| A．Just in | B．After in | C．Just by | D．Only in |