资料题：Visitors praise the English police because（　）。

The English policeman has several nicknames but the most frequently used are‘copper’ and 'bobby'.The first name comes from the verb to' cop' (which is also slang), meaning to 'take' or 'capture' , and the second comes from the first name of Sir Robert Peel, the nineteenth-century politician, who was the founder of the police force 8s we know it today.An early nickname for the policeman was 'peeler' , but this one has died out.Whatever we may call them, the general opinion of the police seems to be a favourable one;except, of course, among the criminal part of the community where the police are given more derogatory(贬义的)nicknames which originated in America, such as 'fuzz' or 'pig' .Visitors to England seem, nearly always to be very impressed by the English police.It has, in fact, become a standing joke that the visitor to Britain, when asked for his views of the county, will always say, at some point or other,'I think your policemen are wonderful.'Well, the British bobby may not always be wonderful but he is usually a very friendly and helpful sort of character.A music-hall song of some years go was called, 'If You Want To Know The Time, Ask A Policeman' .Nowadays, most people own watches but they still seem to find plenty of other questions to ask the policeman.In London, the policemen spend so much of their time directing visitors about the city that one wonders how they ever find time to do anything else!Two thing are immediately noticeable to the stranger, when he sees an English policeman for the first time.The first is that he does not carry a pistol and the second is that he wears a very distinctive type of headgear, the policeman's helmet.His helmet, together with his height,enables an English policeman to be seen from a considerable distance, a fact that is not without its usefulness.From time to time it is suggested that the policeman should be given a pistol and that his helmet should be taken from him, but both these suggestions are resisted by the majority of the public and the police themselves.