速度！帮我写篇英文！要求：假如你是李华，你的笔友David来信询问该如何保持身体健康。整好最近你和同学刚讨论过这个问题。请给笔友写封回信。主要包含：1去除坏习惯：2合理饮食：3坚持锻炼。100词左右

Dear David,     I got your letter asking my ideas on a healthy lifestyle. Now let me tell you what I've got from our last  class meeting on this Subject.     Firstly, we should get rid of any bad habits immediately, like over-sleeping or smoking. Once we get to know how harmful these habits really are, we can stop doing them bit by bit.     Secondly, we should try to have a healthy diet. There is a saying that goes "You are what you eat"．     Finally,it  is important for us to stick to regular outdoor exercise every day.     1 wish you lots of luck!     Yours,