._____ the article four times, I finally understood the author's theory．

_____your composition carefully, some spelling mistakes can be avoided．

_______ shoulder to shoulder with a girl, I felt very embarrassed.

The three college students did what they could _____ the two children, although they was in danger.?

. -What do you think of the book??　
-Oh, excellent. It is worth _____ second time.

. How pleased the detective was _____ what his customer told him!

I hate ______ their complains all day. one of these days I’ll tell them what I really think.

The stone on the river bank rolled under her feet; she was _____into the river，and she called out for help.  

-What did you do yesterday afternoon??
-I went to the bookstore，___ some books and visited my uncle.

________ the two designs, and you will find what problem there is with yours.