20-07-31 最佳食用日期、贩卖期限（保质期）、最佳使用期限。现在你的冰箱和食品储藏室里的物品上可能有许多这种标签。 Best before, sell by, for best results, use by. You probably have many of these labels on items in your fridge and pantry right now. A lot of beha...