Someone knocked at the door he was doing his homework.

下列句中的“以”字，与“不赂者以赂者丧”中的“以”用法相同的一项是

The medicine works more effectively ________ you drink some hot water after taking it.

The train_________at seven o’clock. You’d better get to the station by half past six.

It is hoped that it won’t be long thestudents aren’t burdened with so much homework.