Dear______,
Muchtomyregret/IamterriblysorrythatIamunableto______.ItismainlybecauseatthattimeIwillbefulloccupiedbywhichisquiteoutofmyexpectation,andthatconflictswithyour.ThereforeIamforcedtoadjustmyscheduleandcannotmakemypresenceonyour.Isincerelyhopethatyouwillenjoyagoodtime.Bytheway,canwehavedinnertogethersometimenextweek?Ihopetoseeyousoon.IamreallysorryagainandItrustthatyouwillunderstand.
Yourssincerely,
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