题目内容：

The students are studying hard,for they know_____
A.what they are stuying for B,why they are studying for
上面那个for they know的fpr应该怎么讲?应该选什么?

优质解答

for 是因为的意思
应选 waht they are studying for
what for=why
why 不能再加for了
祝你学习进步,更上一层楼! (*^__^*)
不明白的再问哟,请及时采纳,多谢!