帮忙看看有没有语法错误、谢谢!

题目

帮忙看看有没有语法错误、谢谢!
first of all .when we bought some foods .we should check the date .look at the food if overdue.after then .check the food it fresh or go bad .after shopping ask them the invoice and keep it .in the end .if you find the safety of foods problem .please call at 12315 or find the local consumer association for help .best wishes for you .have a good time
这是关于食品安全的一篇作文。文章开头已经给出
since the CCTV program exposed the wrongdoings by a mcdonald's restaurant in beijing .the safety of food has become a hot topic .what shall we do to fight for our rights and interests

答案

First of all ,when we buy some foods ,we should check the date and look at the food to see if it is over due .Then check the food to see whether it is fresh or not .After shopping ask them for the invoice and keep it .If you find the safety of food problems at last ,please call at 12315 or find the local consumer association for help.Best wishes for you.Have a good time.因为你的错误较多,我重写一遍.希望对你有用.