Question

which的用法

Other states have a sales tax, which is a percentage charged to any item which you buy in that state. 请问这句中的两个which的意思用法， 还有charged 是怎么用的？

Answer 1

关系代词which可以用于引导定语从句。（注意：只用于指事物，不用于指人！！！）
例句：She was not on the train which arrived just now. 她不在刚才到达的那列火车上。

Answer 2

傻了了吧？

Answer 3

which （哪一个）+名词

Answer 4

which只能代表东西或动物：
I want to take away the book which you showed me yesterday. 我想带走你昨天给我看的那本书
当它在从句中作宾语时常常可以省略：
This is the book (which) you want. 这是你要的书。
which还可在从句中作介词的宾语：
The situation which he found himself in was difficult. 他的处境非常困难。

在这种从句中，只有which可以紧跟介词，that则不可以(在最后两个例句中which都不能换作that)。如果which不紧跟介词，则一般可换为that，也可以省略：
This is the house (which/that) I went into. 这就是我进去过的那座房子。

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。