22. —Who______ it be that is knocking at the door?
—It ______ be Father, but I’m not sure.
| A．can; must | B．can; may | C．must; can | D．may; must |
This small mountain village is so perfect a place for holidays that visitors never leave it _________.
| A．feeling disappointing | B．felt disappointing | C．feeling disappointed | D．felt disappointed |
UN Secretary-General Ban Ki-moon left for Pakistan this morning， his assistant _________ him there this Friday.
| A．joins | B．joined | C．joining | D．to join |
The past two years _______ a sharp rise in oil price，which adds to the burden of auto transportation industry.
| A．witnessed | B．witnesses | C．is witnessing | D．has witnessed |
Mr. Duncan raised an unnecessary question __________ he then failed to find an answer.
| A．to which | B．for which | C．with which | D．by which |
Ｉdon’t think Linda could have done such a stupid thing last night，_________?
| A．do I | B．didn’t she | C． did she | D．don’t I |