Havingcheckedeverything,hesatdowntodohishomework, 国语站 题库 8.37K 大中小设置文字大小 问题详情:Having checked everything, he sat down to do his homework, __________ he heard a lightening strike the electricity pole in the backyard. A.for B.when C.or D.but【回答】B知识点:连词题型:选择题 TAG标签:#