how are you doing?为什么do要加ing?而How do you do的do就不需要?

How are you doing? How are you doing? How are you doing? How are you doing? how are you doing how are you ledies doing Hello,how are you doing? how are you doing对么 how are you doing翻译 翻译how are you doing? how are you doing 还是how you doing? how are you doing和how are you的区别 How are you doing 是什麼意思 How are you doing的中文歌词 WHAT IS NEW?HOW ARE YOU DOING? how are you doing tonight?的意思 How are you doing -Aqua 空间链接 how are you doing not bad .