________, no one is sure who discovered America .
It is unfair that such a nice person like Jane ______ lose her job. She works so hard!
— Are you pleased with what he has done?— It couldn’t be ________. He must have put a lot of effort into his work.
— Do you often talk with your friends on the telephone or mobile phone? — _______. I like using QQ.
St. Louis has replaced Camden, New Jersey ______ the most dangerous US city, according to a study based on FBI crime data which was released Monday.
Hellen doesn’t know how much I spent in repairing the house. If she ever found out, I’m sure she me.