Grandfather doesn’t often So he isn’t good in heath.
A. exercises
B. exercise
C. to exercise
D. exercising
网友回答
A. exercises
(答案→)B. exercise
C. to exercise
D. exercising
解析：句意：爷爷不经常锻炼，因此它的健康不佳。结合语境可知本句描述的是反复性动作，故用一般现在时态。句子中已有助动词doesn’t体现时态及人称，故行为动词用原形。选B。