“If you are to succeed, you must put your shoulder to the wheel." my head teacher _______ says to the class.

They wanted to have the house _______ with red wallpaper, which almost drove us ______.

I’m certain David’s told you his business trouble. ________, it’s no secret that he owes a lot of money to the bank..

—Do you know the reason why he failed ?—No, he’s a hard-working man___________, he failed finally.

He knows little of mathematics，______ of chemistry.