---- Our school magazine comes out twelve times a year. ---- Oh, that’s a _____ magazine.
Mr. and Mrs. Green work in the hospital, but they have no children. So they belong to _____.
_____ is a program to help children’s education in poor areas.
About _____ of the world population is Chinese.
We should plant more trees on sides of the street.
your help, we can finish the task in time.