______ she stood up, she dropped the necklace.

I think he's been drinking, _______ I'm not completely sure.

The park is     a beautiful place that     many people come here every day.

—Who broke the window yesterday?—___ Jack ___ Mike. It was Jim.

______ he is very busy, Li Ming always helps others.

The visitors         our factory two days ago.

You will fall behind others _________ you work hard.
A. if                  B. when                C. unless

Mr. Wang has taught in our school _______ he came to Hainan.
A. when                B. for                 C. since          

It was a pity. The game wasn’t on yesterday         the rain.

I am really shy.        I don’t know anyone there?