椅子: chair...
祝贺: to congratulate, congratulations...
公函: official letter...
序言: preface, introductory remarks, preamble, prelude...
违反: to violate (a law)...
顺畅: smooth and unhindered, fluent...
严肃: solemn, grave, serious, earnest, severe...
冷气: air conditioning (Tw)...
冬: (onom.) beating a drum, rat-a-tat...
弱点: weak point, failing...