Which of the following is true according to the passage?

Many large supermarkets are serf-service. When you go into one of these shops, you take a basket and you put the things you wish to buy into this. You queue up at the cash desk and pay for everything just before you leave.
If anyone tries to take things from a shop without paying, they are almost certain to be caught. Most shops have store detectives who have the job of catching thieves. Stealing is considered a serious crime by the police and the courts.
When you are waiting to be served in a shop, it is important to wait for your turn. It is important not to try to be served before people who arrive before you. Many people from overseas are astonished at the British habit of queuing.