Cách sử dụng
A doorbell is a small device that is located on or next to the front door of a house or building. When someone pushes the button on the doorbell, it makes a sound, usually a "ding-dong" noise, to let the people inside know that someone is outside. It is a polite way to announce your arrival to someone's home or business without knocking loudly on the door or yelling. Doorbells are commonly used in many countries around the world, especially in cities and suburbs, and are a convenient way to let someone know you have arrived without disturbing anyone.