Jack is nine years old. Today is his birthday.
--The factory wants to make more cars with _____money.--I think it's impossible.
-- You look_____. Why? --I lost my ID card.
I met Li Lei_____ hospital last Sunday. He was ill_____ hospital then.
The earth will become worse and worse ________ we do something to stop her from being polluted.
I _______ riding my bike________ taking buses to school.