此题要求改正所给短文中的错误。 短文中有10处错误。错误涉及一个单词的增加、删除或修改。

增加：在缺词处加一个漏字符号(＾)，并在其下面写出该加的词。

删除：把多余的词用（＼）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意： 1: 每处错误及修改均限一词。

2: 只允许修改10处，多者（从第11处起）不计分。

Dear Editor,

I’ m writing to tell you about a food poisoning accident. Several days ago, my neighbor ate a bag of food buying from the market. After the meal, they had stomachaches and their faces turn pale. Fortunately, one of their friends found the accident and immediately called on an ambulance, which carried them quickly to a hospital. After several hours’ treatment they final escaped from death. As some illegal businessmen are only interested on making profits to become rich quickly, we seldom care about the necessary safety measures or care which happens to consumers. They must be charged by law. Meanwhile, I do hope whole society can realize the important of food safety and begin taking action together to make sure food is safe.

故障诊断原则是什么？