homework是可數名詞嗎為什么

　　He let us off homework today.

　　他今天免了我們的家庭作業。

　　I still haven't done my geography homework.

　　我還沒做完地理科家庭作業呢。

　　How long did you spend on your homework?

　　你做家庭作業用了多長時間？

　　I've got a lot of homework tonight.

　　我今晚有很多家庭作業要做。

　　Do exercise one for homework.

　　家庭作業做習題一。