Even after harvest, some kinds of produce should be kept apart. Apples, for example, release ethylene gas, a plant hormone. It can cause other foods to ripen too quickly.

• 有些农产品即使收获了也应该分开放。比如，苹果会释放乙烯气体，一种植物激素，该激素能够让其它粮食很快成熟。