My sister exercises in the park every morning .你说把exercises和do erercise都对.可是My sister 是第三人称单数可以用do exercise 真的很麻烦,
问题描述：
My sister exercises in the park every morning .你说把exercises和do erercise都对.
可是My sister 是第三人称单数可以用do exercise 真的很麻烦,
答