In Britain there is a National Health Service (NHS) which is paid for by taxes and National Insurance, and in general people do not have to pay for medical treatment. Every person is registered with a doctor in his or her local area, known as a general practitioner (全科医生) or GP. This means that their names are on the GP"s list, and they may make an appointment to see the doctor or may call the doctor out to visit them if they are ill. People sometimes do have to pay part of the cost of drugs that the doctor prescribes. GPs are trained in general medicine but are not specialists in any particular subject. If a patient needs to see a specialist doctor, they must first go to their GP and then the GP will make an appointment for the patient to see a specialist at a hospital or clinic.
Although everyone in Britain can have free treatment under the NHS, it is also possible for him to have treatment done privately, for which he has to pay. Some people have private health insurance to help them pay for private treatment. Under the NHS, people who need to go to hospital may have to wait for a long time on a waiting list for their treatment. Anyone who is very ill can call an ambulance (救护车) and get taken to hospital for free urgent medical treatment. Ambulances are a free service in Britain. People buy private health insurance in order to ______.