doing exercise helps,为什么help要加s

doing exercise helps,为什么help要加s her father helps her.为什么help要加S He often helps me with my english.这名话里help为什么要加s? He always helps others.为什么helps要加s呢? I hope this helps 为何help要加s? Eating vegetables helps us to keep helthy中的help为什么加s What's more, doing physical exercise helps us shape good per 为什么moring exercises中exercise要加s? exercise 什么时候要加“s”? 为什么 favorite exercise中exercise不用加s 早操英语要不要加s“早操”这个英语morning “exercise”要不要加“s”为什么? doing morning exercise加不加S