You should keep working hard __you have passed the exam.

—All the isatis root（板蓝根） is sold out!—People are crazy!          experts say there is no use eating isatis root to preventH7N9, some people still don’t believe it.

–What do you think of Henan Province? --It’s a wonder place. ____ you go there, you can find many fantastic sights. 

He didn’t take part in the sports meeting, ___he hurt his leg.

I didn’t _____ you were going to leave_____ 3 o’clock.