选D,在led to的后面省略了一个place,那么,这个where the homeless.实际上是一个介词to的宾语从句.如果选in which的话,前面缺少先行词place.空和后面的the homeless people lived不是做led to的宾语吗？从句的lived是不及物动词，所以不缺成分，what和that就错了，那where和in which都可以呀....你说的我有点不明白.the homeless people lived做led to的宾语。从句中的lived是不及物动词，但可以有副词where去做lived的地点状语的。想填in which 的话，必须改写成：we were led to the place/area in which the homeless people lived.还有一个问题，我在网上查了，貌似2L说的副词（where）前确实不能加介词是对的.......那where不是也就不对了..如果where用作名词的话，其前面可以有介词的。如：This includes advice that televisions should be at least two metres from where their children are sitting . 这包括以下这些建议：电视机应该离孩子坐的地方至少两米远。我才看懂，这个句子应该是地点状语从句的吧， we were led to 是被动语态，we就是lead to的宾语呀，怎么会是宾语从句we were led to 是被动语态，we就是lead这个动作的承受者；而介词to后面的成分才是介词to的宾语从句，并没有说 we were led to 是宾语从句。