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l0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：在缺词处加一个漏字符号(∧)，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l0处，多者(从第ll处起)不计分。
Dear Mr. Smith,
I’m very much glad to hear that your shopping centre will build non-smoking supermarket. In my opinion, it’s a good idea to do so, for it can not only help the smokers to smoke less, and it can also do good to other customers’ health. Since you had given up selling cigarettes, the customers don’t like smoking are sure to support you. In addition, smoke in the shopping centre may cause fire, which is dangerous to both your possessions and the safe of the customers. In a word, the non-smoking supermarket will not effect your business. To the contrary, it will help you attract more customers who want to keep health. 
Best wishes!