why do we say morning exercises are good for our health?请问怎么回答

Why do we say that a river is very why do you say that Why do you say that? Why do you say that? why do you say so? why do we say morning exercises are good for our health?请问怎么回答 Why do we say the world will be short of water in the future? Some people say,We learn more outside class. Do you agree?Why or why not?怎么用英语回答 why shall we say thank you? 改错.Why do you say like that? Why Do you Say Goodbye 歌词 tell me why ,why do you cry,every time we say goodbye歌词如下：tell me why ,why do you cry,every time we say goodbye?do you believe,i'm gonna leave you for everthis time?tell me why ,look into my eyes,why can't you see,that i believe in you and why do we study English why do we study English why should we do exercise? Why do we need friends? Why do we need friends? why do we need plants