如何写商函答:商函的书写原则 写信的原则(Writing Principles)已从原来的3(Conciseness, Clearness, Courtesy)发展到目前的7个"C": Completeness, Clearness, Concreteness, Conciseness, Correctness, Courtesy, Consideration)实例 Dear Sirs,Copper Wire With reference to your letter of April 9, we are pleased t...