一．用适当的连接词填空（每空一词）
1.Hardly had we reached home__________it began to rain.
2.It took a few months of investigation __________it became clear.
3.We haven’t been in touch _________we graduated from college.
4.Hard _________it was raining, they went on working in the field.
5.This is an illness that can result in total blindness________left untreated.
6.Because of the heavy traffic, it was already time for lunch break__________she got to her office.
答案：1.when/before 2.before 3.since 4.as 5.if 6.when.
