Do you have any plan for this summer vacation, Mary?— Sure, I’ d like to be a volunteer and help to ______ the Central Park.

He often_______ tennis with his friends. Now they_______ tennis at school.

How____ is the population of the world?

Hurry up, or______ won’t get to school on time.

“I’d like to give my thanks to those__________help my son will be able to survive his terrible disease,” said the woman on TV.