after supper good for your health.A. Walking isB. Walking areC. Walk isD. Walk are

问题补充：

after supper good for your health.

A. Walking, is

B. Walking, are

C. Walk, is

D. Walk, are

答案：

(答案→)A. Walking, is

B. Walking, are

C. Walk, is

D. Walk, are

解析：动名词短语做主语，谓语动词常用单数。