1. Threw off a quick response to the letter.
   一挥而就地写了封回信
2. Had to adhere to the letter of the law.
   必须恪守法律的字面意思
3. He was puzzled how to answer the letter.
   他不知道如何回这封信。
4. I'm composing a formal reply to the letter.
   我正在写一封郑重其事的回信。
5. He advises her to send the letter by airmail .
   他建议玛丽用航空信寄。

　1个副词解释