问题
选择题
Look around when _____ the street.
A.across
B.crossing
C.crossed
D.to be crossing
答案
答案:B
. 当现在分词作时间状语时,前面可以加上when和while.
Look around when _____ the street.
A.across
B.crossing
C.crossed
D.to be crossing
答案:B
. 当现在分词作时间状语时,前面可以加上when和while.