Cách sử dụng
The expression "trade up" is used when someone wants to exchange something they have for something better. For example, if someone has an old car and wants to buy a newer, better one, they might "trade up" by selling the old car and using the money to buy the better one. Similarly, someone might "trade up" in their job by leaving a lower-paying position and moving to a higher-paying one with more responsibilities.