假定英语课上老师要求同桌之间交换修改作文, 请你修改你同桌写的以下作文，文中共有10处语言错误, 每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。增加：在缺词处加一个洞字符号(⋀), 并在其下面写出该加的词。
删除：把多余的词用斜线(\)划掉。
修改：在错的词下画一横线，并在该词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(从第 11处起)不计分，
In order to bring down the number of accident and make drivers aware of the danger of driving much fast, many speed cameras are fixed on the roads. Most of them were placed in bright yellow boxes, so drivers can see it clearly from a distance and slow down. On other hand, some officials have the opposite ideas.They believe hiding cameras are more effective than visible ones. The reason is because drivers, not knowing the exact locations of the cameras, will drive more cautious. The police are now gathered related data to make sure which is good.
