Both his parents look sad．Maybe they ________ what's happened to him．

1. A.
   knew
2. B.
   have known
3. C.
   must know
4. D.
   will know

Both teachers and students _____ not to use mobile phones in class in our school.

1. A.
   are told
2. B.
   are said
3. C.
   told
4. D.
   said

 Both my parents were born ____    1970.

A. at  B. in C. on D. to