You were silly your car, otherwise it wouldn’t have been stolen.
A. not locking
B. to not lock
C. not having locked
D. not to lock
网友回答
A. not locking
B. to not lock
C. not having locked
(答案→)D. not to lock
解析：这题考查不定式做原因状语的用法：不定式的否定形式是to前加not。句意是：你没把车锁上真是很笨，否则它就不会被偷了。选D。