关于英语定语从句的几个问题

Great changes have take place since then in the factory____we are working.
A.where B.that C.which D.in which
选A，where代指in the factory

2.He isn't such a man ____he used to be .
A. who B. whom C.that D.as
选C，若A可选，则B也可，故排除，such..as+短语 such..that+句子

3. He talked a lot about things and person ____they remerberde in the school .
A. which B.that C.whom D.what
选A，代指things and person

4.This machine ,___for many years ,is still working perfectly.
A.afer which I have looked
B . whicn I have looked after
c.that I have looked after
D.I have looked after
前有逗号，排除C，选B，which代指This machine

A where=in which
C such..as+短语
such..that+句子
A 定语从句
B 补充说明

1.Great changes have taken place since then in the factory____we are working.
A.where B.that C.which D.in which
选B.
首先排除A和D.在这类句子中where=in which,但本句子前面已经有了in the factory因而不缺少介词。
其次，将