文中共有10处语言错误，每句中最多两处。错误涉及一个单词的增加、删           除或修改。
增加：在此处加一个漏字符号(∧)，并在其下面写出修改的词。
删除：把多余的词用斜线(＼)划掉。
修改：在错的词下划一横线，并在其下面写出修改后的词。
注意：1. 每处错误及其修改均仅限一词；
2．只允许修改10处，多者（从十一处起）不计分。
Ten years ago, I had worked as a night guard in a factory. On a rainy night, all the lights of factory went out all of a sudden. I rushed out and could see nothing. Lucky for me, the warning system was directly connected with the police station. Three or four minutes late, four police car arrived at the front gate. They searched for the factory carefully, tried to find something unusual. In the end, I am told that the rain had brought about the short circuit, that caused the accident.