31.He has lost key to the locker () some important papers are kept.
问题描述：
31.He has lost key to the locker () some important papers are kept.
a.in which
b.under which
c.inside
选什么,怎么分析的?
答
A
这里先得看意思
表示有重要的文件放在了有锁的存物柜里,得有个介词In
其次,keep in这里少个介词
定语从句用in+which=where