Can you hear someone in the classroom? It is Mary.

Don’t make a noise! They _______on a physics problem now.

Here are some earrings . The owner can’t be a boy. –Well, could be a boy. The earrings might be a present for his mother.

There is no doubt ______ he did is good for us.

Could I finish it today or tomorrow ?—Either day is OK．Take your time．You _________ do it as you like．