题干
They __________ go back home __________ they finished cleaning their classroom.
A：don't; till
B：didn't; till
C：didn't; while
D：don't; and
答案(点此获取答案解析）
B
They __________ go back home __________ they finished cleaning their classroom.
A：don't; till
B：didn't; till
C：didn't; while
D：don't; and
