One third of the country _____ covered with trees and the majority of the citizens _____ black people.

There ________ some tomatoes and milk in the box, but now there aren't any.

We all feel it is Jack as well as his wife that 　　　　 for their son's bad performance at school.

Buying clothes     a hard job because the clothes a person likes        not very often fit him or her. 

 — Each of the students, working hard at their lessons, ______the book.  — So have I.