写给儿子的一封家书(怎么写一封有效的英文推广信)
I am writing to introduce a new product that I believe you will find useful. [Product] is designed to help [describe purpose or benefit of product].
I am writing to introduce a new product that I believe you will find useful. [Product] is designed to help [describe purpose or benefit of product].
I am writing to introduce a new product that I believe you will find useful. [Product] is designed to help [describe purpose or benefit of product].