My sister gave me a record which is very interesting 可不可以这样理解：

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你上面的理解有点不恰当.应该这样理
分为两句
My sister gave me a record.
The record is very interesting.
以后所有的这样的 which 引导的从句,都可以如上这样分两句来理解.
which 就是指 出现在which 前面的那个 名词 （或词组）,这里which 就指 the record.
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以下情况是比较复杂的用法,你目前可以直接忽略它.
最好在你 能够 熟练运用 which 之后,再看这样的句子.
比如:（注意 record 后面有个逗号）
My sister gave me a record,the cover of which is very interesting.
这里的 which 还是指 the record ,分两句：
My sister gave me a record.
The cover of the record is very interesting.