Answer the doorbell, please. It must be your uncle. —It Heidi. She’s coming over this morning to help me with my math.

There is _____ knocking at the door. Go and see who it is.

Is your brother a League member?—Yes, he____ the League threeyears ago. He____ a League member for three years

Can you image that the CEO of Pu Tian Software Companydoesn’t __________ dress

The recent survey found that ____________ of working mothers would prefer to stay at home.