The tower which is on the corner of the street is large.
本句中, 若是采用定语从句的表达形式,则是对于the tower 起到限定的作用.
如果是 把 which is 去掉, 则成为The toweron the corner of the street is large.
即介词短语 on the corner of the street 作为后置定语修饰 the tower ,
结构发生了变化,不过句子含义不变.
（位于街角处的那幢高楼很雄伟 ）