Someone knocked at the door he was doing his homework.

Drink driving should be treated as a crime ________whether the driver causes a crash

Does he often ask you for help—Oh，no，only________.

A teacher’s________to the cause of education is worth great respect of the whole society because it brings countless benefits to the development of society.

The survey shows that 200 students do different thingsduring their vacations. ______ of them take classes according to the survey.