31. Which of the following is true about Madrid’s clean air zone?

　　A. Its effects are questionable.

　　B. It has been opposed by a judge.

　　C. Its fate is yet to be decided.()

　　D. It needs tougher enforcement.

　　32. Which is considered a weakness of the city-level measures to tackle dirty air?

　　A. They are biased against car manufacturers.

　　B. They prove impractical for city councils.

　　C. They are deemed too mild for politicians.

　　D. They put too much burden on individual motorists.()

　　33. The author believes that the extension of London’s Ulez will .

　　A. arouse strong resistance.()

　　B. ensure Khan’s electoral success.

　　C. improve the city’s traffic.

　　D. discourage car manufacturing.

　　34. Who does the author think should have addressed the problem?

　　A. Local residents

　　B. Mayors.

　　C. Councilors.

　　D. National governments.()

　　35. It can be inferred from the last paragraph that auto companies .

　　A. will raise low-emission car production

　　B. should be forced to follow regulations()

　　C. will upgrade the design of their vehicles

　　D. should be put under public supervision