I do not know why I am very sad

Why I do not know I do not know why this happened! I do not know why I am very sad I do not know I do not know Do not know why I become so active!是什么意思 i do not know why my mother seems (be)happy Why l do not know.This is my feel.Understand?I do not know your mean. I do not know why,I can not forget you,I still like you! what i do not know is that why...是不是应该改为is it that why啊 请问 I DO NOT KNOW sorry,i do not know! I do not know why I fell in love with you什么意思 怎么读I do not know why,I will tell you,you are my night sky. Do not know why,I secretly Fall in love with you,and you did not find. Very simple,we do not know,why do I speak to you so much ah. I love you Why You Do not Know My Why do not you trust me I said I'll wait f上面的意思是什么? 谁能说下 i do't know why this days