DearSarah,
IamterriblysorrytotellyouthatIamunabletoattendyourbirthdaypartnextThursdayevening.Thatisowingtothefactthatmyyoungerbrothersuddenlyfellillandwastakentoahospitalthismorning.Ihavetogothereimmediatelyandtakecareofhim.Astoldbythedoctorincharge,itwilltakearoundfivedaysforhimtorecoverandIhaveaskedmybossforaleave.
IreallyregretthatIcannotgotocelebrateyourbirthdaypersonallyandwouldmisstheperfectchanceofenjoyingmyselfwithallouroldfriends.Ihavechosenasmallgiftforyouandwillsendittoyoutomorrowtoshowmybestwishes.Besides,pleasegivemyregardstoourfriendswhenyoumeetthemattheparty.
Cordially,
Xuexila