Dear Sir or Madam:
With reference to your letter on Dec.23rd,i'd like to ,first of all,convey my deepest appreciation to your offering me the position of manager assistant in your company.And i am more than delighted and honored to gain your trust and assignment.
However,i have to decline this unexpected offer whih all unwillingness, which mainly results from an abrupt change in my schedule. when i applied for the position a week ago , i aslo sent an application to cloumbia University, for i hadn't yet made up my nind whether to start work afger graduation this month . What a coincidence ! i got the adminttance to the graduate school of English literrature in Columbia University the same day i received your letter. Weighing the pros and cons for an entire night ,i determine to seize the changce for further study abroad.
With my earnest apology, i do hop you can pay me due understanding and forgiveness for turning down your offer. in closing ,may your company have great prospects and enjoy extensive popularity.