1) According to the standards of the relevant state departments, the shelf life means: "The food is still edible under the conditions specified in the label".

Therefore, "second-hand" refers to food, because food has a shelf life. The shelf life is related to the production date, and has nothing to do with whether it is second-hand. Food must have a shelf life.

2) Warranty means that if the machine has problems within the specified period, the dealer is responsible for the maintenance, but whether it is necessary to pay compensation depends on the warranty agreement.