China’s first compulsory safety regulation on primary buses, which requires every seat to have a seat belt, will ____ on July 1.
They will never succeed, _____ hard they try.
_____ still half drunk, he made his way home.
_____ she was very tired, she went on working.
Busy _____ he was, he tried his best to help you.
I learned a little Russian _____ I was at middle school.