good exercise.
A. Climbing hills is
B. Climbing the hill is
C. The climbing hills are
D. The climbing of hills are
网友回答
(答案→)A. Climbing hills is
B. Climbing the hill is
C. The climbing hills are
D. The climbing of hills are
解析：考查动名词作主语。动名词短语作主语，hills泛指，不需要冠词，选A。