假如你是李华，上周从一网店购买了一个（网络）路由器，使用过程中发现有网络经常掉线，WIFI信号不稳定等问题，为此你给网店的售后客服写一封信，要求更换产品或全额退款。
注意：1. 词数为100左右；
2. 可适当增加细节，以使行文连贯。
参考词汇：路由器router 服务器server 掉线lose connection to 稳定的stable
[谋篇布局]
应用文的实际用途决定了其语言要简洁明了。主要有三个原则，即proper（恰当）、 precise（精确）和polite（礼貌）。具体要求体现为：需开门见山，文章一开始就要表明意图；行文逻辑清晰、目标明确；语气要恰如其分，注意语言的正式和礼貌，遵循交际原则。
高考书面表达多以日常生活场景为基础。在扩充细节的时候，同学们要结合平时的生活积累，在符合常识的基础上，充分发挥想象力。
投诉信作为英语文体的一种，目的是解决问题，比如消费利益受损、正常生活和工作受到干扰等。内容可包括：说明投诉的原因并表达遗憾；实事求是地阐述问题发生的经过；指出问题引起的后果；提出批评及处理意见，要求对方采取措施。此外，语气注意要冷静、郑重、克制，不必过于礼貌。但也要就事论事，不能人身攻击。
[常用表达]
开头常用句式
I am writing to you to complain about …
I am writing to express my dissatisfaction/disappointment/concern about …
I am writing to inform you that I am dissatisfied with …
I feel sorry to trouble you but I am afraid that I have to make a complaint about …
I wish to draw your attention to the problem/fault …
I regret to inform that …
结尾段常用句式
I will appreciate it very much if you could …
I look forward to your dealing with these problems without delay.
I hope you will consider my suggestions and improve the situation as best as you can.
We hope that you will consider this matter seriously and make an effort to prevent the recurrence of this kind.
I hope you can give me a satisfying reply and deal with this matter reasonably.
I must have you fully understand that without a satisfying solution， I will reserve my right to take legal action.
其他常用句式
The reason for my dissatisfaction lies/consists in …
Under these circumstances， I find it difficult to …
For one thing …， for another …
Therefore， I hope to change for another … or declare a refund.
I received such poor service that I felt I should bring it to your attention.
习作一
Dear Sir or Madam，
I am writing to you to complain about the router which I bought last week from the internet.
I found some problems during I use it. First， I can’t find the servers when I looking through the news. Second， it was often losed connection to the servers if I was finding some informations from the internet. It caused big problems to my work and daily life. The most serious doubt is the WIFI doesn’t stable. Sometimes it lose connection to the server in a second. After a while， it come to be fine.
Because of the problems， I require to full require or change a new one. If you can change a new one， it will be the most wonderful way to solve these problems.
I’m looking forward to hearing from you.
Yours sincerely，
Li Hua
这是一篇中低档习作，得分18。其优点是：
1. 作者运用了衔接词，观点清晰，层次分明。
2. 活学活用了一些短语，如because of， after a while， look forward to， look through。
不足之处是：
1. 存在简单单词拼写错误。如：lose过去式应为lost；information是不可数名词，复数的形式不加s。
2. 时态、语态混乱。在第2段描述产品问题时，应统一用过去时态。如第2段第2句应改为I couldn’t connect the server when I was looking through the news. it was often losed connection to应改为it often lost connection to。
3. 中式英语过多，还有一些表达错误：第2段中的… during I use it应改为when I used it；it come to be fine应改为it turned out to be fine；第三段的I require to full refund应改为I require a full refund.
习作二
Dear Sir or Madam，
I am writing to you to complain about the poor quality of the router I bought from your store last week.
Having used it for several days， I found the router seemed to have been out of order and problems have arisen one after another. While I was searching for some information on the internet， it lost connection to server frequently， which annoyed me greatly. What made matters worse was that the signal of wireless network was not stable， which made it difficult for my iphone or ipad to connect to the net via WIFI， putting me to great inconvenience.
Therefore， I would be grateful if you could replace it with a new one as soon as possible. If not properly settled， a full refund would be acceptable as well. Thank you for taking it into consideration， and I’m looking forward to your early reply.
Yours sincerely，
Li Hua
这是一篇高档习作，得分23。
1. 要点齐全，细节补充合理。第2段实事求是地阐述产品问题，逻辑清晰，有条有理。第3段提出解决建议，语气郑重礼貌，不卑不亢。
2. 亮点词汇短语表达运用得当。如：seem to have done， out of order， arise， search for， put sb. to great inconvenience， take sth. into consideration.
3. 长短句并存，句式灵活多样，文章节奏感强，语用能力突出。如：
Having used it for several days， I found the router seemed to have been out of order and problems have arisen one after another. （现在分词完成式作状语）
What made matters worse was that the signal of wireless network was not stable， which made it difficult for my iphone or ipad to connect to the net via WIFI， putting me to great inconvenience. （主语从句+非限定定语从句+现在分词作结果状语）
If not properly settled， a full refund would be acceptable. （条件状语从句的省略）