21. –Mum, I’m so hot and thirsty.
-Here’s the money , dear. Go and buy ________an ice cream.
A .you B. me C. yourself D. myself
22.It’s reported that the sand storm is moving__________ the south year after year.
A. on B. towards C. beside D. below
23.-Did you visit Tom yesterday?
-No. When I got to his house, he________.
A. left B. would leave C. has left D. had left
