6. His effort of decades began to ______. He came to be well-known for his findings.

   A. pay off         B. die off            C. put off              D. break off

7. The ______ of lung cancer is particularly high among long-term heavy smokers, especially chain smokers.

   A. incident        B. accident           C. incidence            D. evidence

8. Nothing is so uncertain as the fashion market where one style ______ over another before being replaced.

   A. dominates      B. manipulates        C. overwhelms            D. prevails

9. Mrs. Brown couldn’t shake the ______ that these kids were in deep trouble and it was up to her to help them.

   A. conversion     B. conviction         C. conservation            D. convention

10. The philosophy class began with twenty students but ______three after the mid-term exam.

    A. picked up      B. turned out         C. dropped out        D. kept up

6--10  ACDBC