java拼接字符串加逗号:帮我改改谢谢大家

Dear Sir ，
I\'m really sorry to tell you that your walkman\'s qulity need to be improved. （其实没有必要感到抱歉，原句的用法不太对。）I bought it form your store recently（recently这个词一般用完成时） ,I came back my school.（I came back to my school这句话可以删去，） But ,I found that there were some wrong with the walkman. The walkman looked very nice, but it did not work sometimes（修改）.
Firstly, I thought that the charge powered off. Sowly , I am sure that it must be walk man quality promble.（改为Secondly , it must be the matter of the guality.） I am really hate to complain, but this one thing is really disturding. 改为I don\'t want to explain too much,but it\'s really disgusted
As a student, I just want to improve my english as quickly as I could. But now , the walkman is bad, I have wasited so much time for it.(改为because of it)
What you choose to do with the piece of information is entierly up to you.
I am looking forward to your reply。

（Your） friendly
ryan

^^个人意见仅参考，祝作文越来越好。

Dear Sir

I am really sorry to tell you that there should be cause to complain about your walkman qulity.I bought it form your store recently ,(改为)
( I am writing to complain about the walkman's quality which i have just bought from your store recently.

I came back my school. But ,I found that there were some worry with the walkman.(改为)
I found that there was something wrong with my walkman.

The walkman looked very nice, but it did not work some times.(改为)
( I personally am satisfied with the appearance.However, it did not really function that well.

Firstly, I thought that the charge powered off.
( At first,I thought that it could be the charger problem.)

Sowly , I am sure that it must be walk man quality promble.
( After observation, i realise that it is actually the quality problem.)

I am really hate to complain, but this one thing is really disturding.
( I am a person who hate to complain, but this is really disturbing.)

As a student, I just want to improve my english as quickly as I could.
( As a student, I would like to improve my english as fast as possible.)

But now , the walkman is bad, I have wasited so much time for it.
( Nonetheless, due to the walkman's bad quality, i am wasting most of my time on it)

What you choose to do with the piece of information is entierly up to you.
( I hope you could take consideration of improving your walkman's quality.)

I am looking forward to your reply。

Your friendly (Yours sincerely)
ryan

大概是这样吧