A. think   B. thank   C. thinks   D. are thinking
    10. Doing morning exercises _____ good for our health.
    A. be      B. are     C. is      D. am
    11. Everyone likes people who _____ ready to help others.
    A. is      B. are    C. being    D. was
    12. The Smith family _____ making dumplings in the kitchen.
    A. is      B. are     C. has been    D. can
    13. One third of the population in our city ______ farmers in the past.
    A. are     B. were      C. is      D. was
    14. The headmaster and the teacher ______ coming to us now.
    A. are      B. is       C. will      D. am
    15. Tom as well as his friends _____ skating every Saturday.
    A. are       B. is      C. go      D. goes
    （Keys： 1. B  2. C  3. B  4. C  5. A  6. C  7. B  8. B  9. A  10. C  11. B  12. B  13. B  14. A  15. D）