Is _______ necessary_______ the workers wear uniforms at work?A. it, for B. this, to C. it, that
We teachers should ______ students ______ us questions in class.
— I have trouble ______ my new computer.— Don’t worry. I will show you ______.
It’s dark. I would rather ______in bed than ______a walk outside.
My dream is to be a singer one day and I will do what I can do __________ my dream .
— Why do you think ______? — He could ______ for exercise.