When he knocked at the door, my mother was busy ____ supper.
| A．preparing for | B．in preparing |
| C．to prepare for | D．to prepare |
_______are the days when we used foreign oil
A To goB Going C Go D Gone
.It is the house________I have ever lived________is under repair
A which, that B that ,which C in which ,where D where, that
___________harder, he would have succeeded in the college entrance examination
A He worked B He had worked C Had he work
edD Did he work
__________ abroad for two years ,he will come back within two weeks
A Having studied B Studied C To studyD Studying
A boy rushed in_____________he opened the door
A the momentB for the momentC for a momentD at the moment