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 Automobile 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 across 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.
答案：26.A 27.C 28.C 29.A 30.B