Though many of the heavy smokers have realized the serious effect that smoking has their health, they continue to smoke instead of .
A. for; giving it up
B. on; quitting
C. to; abandoning
D. on; leaving
网友回答
A. for; giving it up
(答案→)B. on; quitting
C. to; abandoning
D. on; leaving
解析： 考查固定搭配。the serious effect是先行词，that smoking has their health是定语从句，把先行词代入定从，是 smoking has the serious effect health，构成have an effect on 结构，所以第一空用on;根据句意：他们继续吸烟而不是戒掉。Quit停止，终止。所以选B。