To help the sick people in the hospital is _____ for me .
The bus driver always says to us: “Don’t get off ______ the bus stops.”
________ of the city was covered with the heavy smog.
---Can you come on Monday or Tuesday, John? ---I’m afraid _______ day is possible. I will be very busy on those two days.
We’ve decided to decorate our new flat by ______ this weekend.
_____March 20____26, the US first lady Michelle Obama was on a trip to China with her daughters and mother.