He made another wonderful discovery, _____ of great importance to science．
| A．which I think is | B．which I think it is |
| C．which I think it | D．I think is |
. The house is nice, but ______ too small for a family of five.
| A．rarely | B．fairly | C．rather | D．pretty |
______ from what he said, he must be the thief who has stolen the car.
| A．Judging | B．Judged | C．To judge | D．Judge |
. They were surprised that a child could work out the problem ______ they themselves couldn’t.
| A．once | B．while | C．then | D．if |
. --- I hear Jane has gone to the Holy Island for her holiday.
--- Oh, how nice! Do you know when she ______ ?
| A．was leaving | B．had left | C．has left | D．left |
. The factory was built in a secret place, around _____ were high mountains.
| A．where | B．it | C．that | D．which |