what are the qualities in constructing an effective business letter?
['Clarity: ADVERTISEMENTS: ... ', 'Conciseness: Transmission of maximum information by using minimum words should be the aim of letter-writing. ... ', 'Completeness: ADVERTISEMENTS: ... ', 'Correctness: ... ', 'Courtesy: ... ', 'Cheerfulness: ... ', 'Promptness: ... ', 'Appropriateness:']