【正确答案】
Dear Amy，
I wonder if I could boow your MP3 for a few days．As you know,tomorrow I am going to interpret for a conference．I really want to record my interpreting for later reference．But，just now I found my MP3 was broken．And it's too late for me to have it fixed．You are the only one I can think of to turn to for help．I promise that 1 will be very careful of your MP3 and make no damage done onit．
Your timely help will be greatly appreciated．I look forward to your early reply．Thank you very much!

【答案解析】[样文评析]
这篇便条的主要目的是向朋友借用MP3。
根据便条的要求，考生首先需要说明自己想要借用朋友的MP3；之后解释原因，注意这里提供的原因要具有一定的合理性；最后，根据此处具体情况的需要，考生还应表示自己会仔细使用及保护朋友的MP3，并表示等待回信，表示谢意。
由于交流双方是朋友关系，便条应为非正式文体，语言表达上要比较口语化，并带有一定的感情色彩。