＿＿＿used to be thought that the earth was square. 

I did not accept any of the many offerings,because I found_____satisfactory.

I’d appreciate _______ if you would teach me how to use the computer.

Some people would rather ride bikes as bike ridding has_________ of the trouble of taking buses.

There is only one book of this kind left here, I wonder if you still want to buy____.