关系代词引导的定语从句

　　关系代词所代替的先行词是人或物的名词或代词，并在句中充当主语、宾语、定语等成分。关系代词在定语从句中作主语时，从句谓语动词的人称和数要和先行词保持一致。

　　which, that

　　它们所代替的先行词是事物的名词或代词，在从句中可作主语、宾语等。

　　例如：

　　A prosperity which / that had never been seen before appears in the countryside.

　　农村出现了前所未有的繁荣。（which / that在句中作宾语）

　　The package (which / that) you are carrying is about to come unwrapped.

　　你拿的包快散了。（which / that在句中作宾语）