Questions 26 to 30 are based on the following passage:
　　Believe it or not，optical illusion (错觉) can cut highway crashes.Japan is a case in point.It has reduced automobile crashes on some roads by nea rly 75 percent using a simple optical illusion.Bent stripes，called chevrons (人字形)painted on the roads make drivers think that they are d riving faster than they really are，and thus drivers slow down.Now the American Association Foundation for Traffic Safety in Washington D.C.is planning to rep eat Japan's success.Starting next year,the foundation will paint chevrons and other patterns of stripes on selected roads around the country to test how well the patterns reduce highway crashes.Excessive speed plays a major role role in as much as one fifth of all fatal traffic accidents,according to the foundation .To help reduce those accidents，the foundation will conduct its tests in areas where speed - related hazards are the greatest - curves，exit slopes，traffic c ircles，and bridges.Some studies suggest that straight，horizontal bars painted across roads can initially cut the average speed of drivers in half.However，t raffic often returns to full speed within months as drivers become used to seeing the painted bar.Chevrons，scientists say，not only give drivers the impress ion that they are driving faster than they really are but also make a lane sppea r to be narrower.The result is a longer lasting reduction in highway speed and the number of traffic accidents.
　　26. The passage mainly discusses .
　　A) a new way of highway speed control
　　B) a new pattern for painting highways
　　C) a new approach to training drivers
　　D) a new type of optical illusion
　　27. On roads painted with chevrons drivers tend to feel that.
　　A) they should avoid speed - related hazards
　　B) they are driving in the wrong lane
　　C) they should slow down their speed
　　D) they are approaching the speed limit
　　28. The advantage of chevrons over straight，horizontal bars is that the former .
　　A) can keep drivers awake
　　B) can cut road accidents in half
　　C) will have a longer effect on drivers
　　D) will look more attractive
　　29. The American Association Foundation for Traffic Safety plans to .
　　A) try out the Japanese method in certain areas
　　B) change the road signs across the country
　　C) replace straight，horizontal bars with chevrons
　　D) repeat the Japanese road patterns
　　30. What does the author say about straight，horizontal bars painted acr oss roads?
　　A) They are falling out of use in the United States.
　　B) They tend to be ignored by drivers in a short period of time.
　　C) They are applicable only on broad roads.
　　D) They cannot be applied successfully to traffic circles……