问题补充:
David watches TV six hours a day and eats much junk food, but he never exercises. So he is .
A. healthy
B. unhealthy
C. serious
D. smart
答案:
A. healthy
(答案→)B. unhealthy
C. serious
D. smart
解析:四个选项含义分别是健康的、不健康的、严重的和精明的。从前文David一天看六个小时电视,吃许多垃圾食品,从不锻炼,因此身体应是不健康的,所以选B。