Question

8．步行有益健康．
Walkingis good for your health．

Answer 1

分析 is good for．

解答 答案：is good for．这里是说客观事实用一般现在时，表示对…有益，用be good for，主语是动名词walking，谓语动词用单数，故is，故答案是is good for．

点评 非谓语动词作主语时谓语用单数．但是如果是两个并列的就象是两个名词并列时候就用复数了．To learn english well，listening is very important．
listengling作主语，动词用is
To learn Enlish well，listening and speaking are very important．
这句话中主语是listening和speaking，所以用了动词are