Drinking milk every day is good ___ our health. [ ]

Do you know________woman in red? —Yes,she’s a professor of________university.

I can’t give my son the leading position. ______, he is too young; secondly, I want Mr. Smith to have the job.

Whose is this blue bike? －It ________ be Mary’s. Her bike is black and white.

What are you going to buy _______the money? —A big house. [ ]