He has lost the key to the drawer the papers are kept. A. where B. on whichC. under which

He has lost the key to the drawer the papers are kept.
A. where
B. on which
C. under which
D. which

(答案→)A. where B. on whichC. under whichD. which解析：句意：他把钥匙落在了那个放卷子的抽屉里。这里是一个定语从句，先行词the drawer表示的是地点，所以用where引导的定语从句，它在从句中作地点状语，on which及under which有时也等于where，但是在这里强调的是东西被锁在了抽屉里，故答案选A。

这下我知道了