3）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）
.