___ most of the earth’s surface is covered by water, fresh water is very rare and precious.
| A．As | B．Once | C．If | D．Although |
He dressed up and went to the party as if ___________.
| A．was invited | B．had been invited |
| C．invited | D．to be invited |
She may have missed the train, in _____ case she won't arrive for another hour.
| A．whose | B．that | C．which | D．what |
We’ll be free tomorrow，so I suggest ______ to the history museum.
| A．to visit | B．visiting | C．we should visit | D．a visit |
— I phoned you yesterday morning. A girl answered, but I didn’t recognize the voice.
— Oh, it ____ my younger sister. She was in my room at that moment.
| A．must have been | B．should have been |
| C．could have been | D．may have been |
Not far from the club there was a garden, ____ owner seated in it playing bridge with his children every afternoon.
| A．whose | B．its | C．which | D．that |