which 语法问题the air is good,which make me happy.which能这么用吗

可以
* which的特殊用法：
在非限制性定语从句中，which可以代表主句的一部分甚至全部，而不仅限于一个名词或代词，而which引起的从句用作修饰整个主句：
This I did at nine o’clock, after which(=doing it) I sat some time reading the paper. 我九点钟坐了这事，之后我就坐着看了一会儿报纸。
He invited us to dinner, which was very kind of him. 他请我们去吃饭，这是他难得的好意。
which在从句中还可用作定语：
He advised me to hide behind the door, which advice I took at once. 他让我躲在门后，我立即照做了。
He studied computer science, which knowledge is very important today. 他学的是电脑，这门知识现在很重要。
which有时代表后面的意思：
He hung around for hours and，which was worse，kept me from doing my work.
他闲呆了好几个钟头，更糟糕的是，这使我也没法工作。
在书面语中，有时还把这类从句写成独立的句子：
From which he learned a few lessons which were later of value to him. 从中他得到了一些教训，对他后来很有用处。
which还可和不定式一起用：
Allow me one minute in which to change my costume. 给我一点时间换装。
She has a little money in the bank, with which to help her mother. 她在银行存了一点钱，用这钱帮助她的母亲。