A: content straight to the point, and dont write poem word.
B: apply for different employers and industry, and your cover letter will act according to actual circumstances, cant with changeless should changing.
C: put forward you can make anything for the future employer, not for what you do.
D: concentrate on specific career goals.
E: dont say no marginal words.
F: dont write without strength of the empty talk.
G: should not be more than one page, unless you are applying company for further information.
H: to any printing or the spelling mistake have to be carefully again carefully.