Fast food is relatively cheap, comparing with traditional food. It may cost as low as a few dollars with no service charges or tips at all. It is highly accessible, which many of those fast food restaurants open 24 hours a day 7 days a week with no prior reservation required, and is ready to serve as soon as when people have just finished their orders. People have the choice of to dine in, take away or even drive through for their meals. These advantages, which fit and match the city life style seamlessly, make fast food so attractive and irreplaceable.