Generally speaking, it is recommended to use plastic wrap for leftovers in the refrigerator, which can not only slow down the evaporation of water in food, but also reduce the volatilization of food taste and reduce the odor with other foods in the refrigerator to some extent. Plastic wrap can also help food reduce contact with other bacteria in the refrigerator, which helps to prolong the preservation time of leftovers. But the dishes that have just come out of the pot can't be covered immediately. After the vegetables are completely cooled, cover them with plastic wrap to protect vitamin C.