问题补充:
If you want to be healthier, you shouldn do in the classroom all the time but do more on the playground.
A. exercise; exercises
B. exercise; exercise
C. exercises; exercises
D. exercises; exercise
答案:
A. exercise; exercises
B. exercise; exercise
C. exercises; exercises
(答案→)D. exercises; exercise
解析:如果你想要更健康,你不应该一直在教室里做体操,而是在操场上做更多的锻炼。Exercise做锻炼和练习的意思讲时,是不可数名词;当做某种体操眼保健操等时是可数名词。结合语境可知选D。