听力原文： London taxi drivers know the capital like the back of their hands, no matter how

small and indistinct the street is, the driver will be able to get you there without any trouble. The reason that London taxi drivers are so efficient is that they have all gone through a very tough training period to get the special taxi driving license. During this period which can take from 2 to 4 years, the would-be taxi driver has to learn the most direct road to every single road and every important building in London. To achieve this, most learners go around the city on small motorbikes, practising how to move to and from different points of the city.

Learner taxi drivers are tested several times during the training period by government officers. Their exams are terrible experience. The officers will ask you, "How do you get from the Buckingham Palace to the Tower of London？" And you have to take them there in the direct line. When you get to the tower they won' t say "well done!' They will quickly move on to the next question. After 5 to 6 questions, they will just say "see you in two months lime", and then you know the exam is over.

Learner drivers are not allowed to work and earn money as drivers, therefore many of them keep their previous jobs until they obtain the license. The training can cost quite a lot because learners have to pay for their own expenses on the tests and a medical exam. SECTION C NEWS BROADCAST

London taxi drivers arc very efficient ______

A．because they have a driving license

B．because they have received special training

C．because the traffic conditions in London are good

D．because the traffic system of the city is not very complex