Take the varieties of Zhengshang Institute as an example, one is that the opening fee is the same as the closing price in the day, such as urea, staple fiber, peanuts and other varieties. One is the warehouse free of charge, such as vegetable oil, sugar, red dates and so on. In addition, opening a warehouse in one day is more expensive than opening a warehouse in one day. For example, the daily opening fee for methanol is 2 yuan, the opening fee for apples is 5 yuan, and the opening fee for apples is 20 yuan.