He has lost the key to the drawer the papers are kept.
A. where
B. on which
C. under which
D. which
网友回答
(答案→)A. where
B. on which
C. under which
D. 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。