21. This restaurant has become popular for its wide_________ of foods that suit all tastes and pockets.
Ten minutes later,a bus________and everybody got on it.
I have some trouble________physics.I would be grateful________you if you could give me some advice on it.
—Have you ever been to Shanghai Expo Garden? —No.It is the first time that I________to China.
You look well.The air and the sea foods in Sanya must ________you.I suppose.
Emily’s grandma________poor health for several years,so she always takes care of her after school.