Choose the appropriate form of a modal verb:
1.      .....you tell me the time, please?
     a) do you have to...  b) must...  c) could...    d) may...
2.  If you have fever and a headache you .... stay at home and call a doctor.
    a) must   b) can    c) may   d) should
 3.  Our students .... bring their student's books to school, we have some extra copies in the classroom.
    a) mustn't  b) shoudn't  b) don't have to   d) can't 
4. You ... always wear a uniform at school.
    a) can  b) must b) should  d) may