During the whole time of last week I had though my Mp3 didn't function well. As I need to practice listening comprehension on the way to my office in order to squeeze time for improving english skill. My MP3 run well but has no sound output.  I don't think the earphone is broken and there is only poor contact between the plug and audio hole. But due to my carelessness I think earphone is  a part of the MP3 and it can't be detached from the MP3. As a result I will have to buy a new MP3. When I bought a new MP3 on saturday and found that the earphone can be detached from the device, I want to return the new MPS to the store for a new earphone. At first the  counterjumper didnot agree with it. At last they insist on subsistuting a earphone with the same price for the new MP3. The price of MP3 is 158 yuan. So is the price of earphone. How expensive this earphone. I never dream of buying such a  expensive earphone. I am so regretful about my carefulness.