Dear__________,
I am writing this letter to call on_________.Assome of you may know,________.In face,________.
It is necessary for us to________.On the onehand,__________.On the otherhand,_________.Hesce, it is hightime________.Firstly, we should_____________.Secondly,___________.
Please contact us via_________.Please join us inthe effort to __________.
Thank you for your paiticipation~
Sincerely,
____________