Questions 17 to 20 are based on the passage you have just heard.

　　17. 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.

　　18. A) Two to four months.　　　　　　　　　　C) At least half a year.

　　B) About three weeks.　　　　　　　　　　　D) Two years or more.

　　19. A) Government officers are hard to please.

　　B) The learner has to go through several tough tests.

　　C) The learner usually fails several times before he passes it.

　　D) The driving test usually lasts two months.

　　20. A) They don't want their present bosses to know what they're doing.

　　B) They want to earn money from both jobs.

　　C) They cannot earn money as taxi drivers yet.

　　D) They look forward to further promotion.