Cross references : dependent clauses and phrases ; clauses -- restrictive and nonrestrictive .
参考:从属从句和短语;限制性从句和非限制性从句。
When writing a nonrestrictive clause , do place a comma before " which . "
前一定不要用逗号，而使用非限制性从句时，which
The nonrestrictive clause in " I always buy his books , which have influenced me greatly , " refers to his books generally and adds an additional fact about them .
在“我总是买他的书，那些书对我影响极大”一句中，非限定性定语从句一般是针对他的书进行附加性修饰。
Nonrestrictive clauses simply add further information about preceding antecedents , but they do not limit or restrict the meanings of the referents .
非限制性子句仅是对前面的先行词提供更进一步的资讯，但未限定其指涉对象的含义。
Although some writers use " which " to introduce a restrictive clause , the traditional practice is to use " that " to introduce a restrictive clause and " which " to introduce a nonrestrictive clause .
