问题
选择题
From time to time a crocodile has snatched someone _______ he or she is even aware that the crocodile is there.
A.when
B.until
C.since
D.before
答案
答案:D
考查时间状语从句。句意“有时候,在人们意识到有鳄鱼之前,鳄鱼会突然捉住他。”A“当”;B“直到”;C“自从”;D“在......之前”。故选D。