11. The number of students who (withdraw) ___________from class since the term began

      (be) ___________quite high.

12. There (be) at least one window in every room.

13. A lot of students in my class (speak) ___________ and (undrstand) ___________ Spanish.

14. The trousers Lan’s bought (not, go) ___________ best with her shirt.

15. The information she gave me (be not) ___________valuable.

16. The number of days in a week (be) ___________seven.

17. Either you or he (have) ___________to do the task.

18. Two years without a job (be) ___________too long to be.

19. Every girl and boy (be) ___________required to have certain immunizations before enrolling in public school.