I read that macbook can be renewed in the United States, but Chinese mainland has never had such a policy, so you don't have to think about it.

Some computer specialty stores use the slogan of "trade-in", which is just a promotional advertisement for their stores. The computer will give it to them to evaluate and see how much it is worth. You can get a new computer only by paying a certain amount of money. In fact, this is just to get you to pay for a new computer and recycle your old macbook at a low price.

If the old macbook is bought in a short time and the color is good, it is better to hang it on the second-hand trading section of the post bar forum and sell it.