Dear__________,

　　I am writing this letter to call on_________.As some of you may know,________.In face,________.

　　It is necessary for us to________.On the one hand,__________.On the other hand,_________.Hesce, it is high time________.Firstly, we should _____________.Secondly,___________.

　　Please contact us via_________.Please join us in the effort to __________.

　　Thank you for your paiticipation~

　　Sincerely,

　　____________