题目内容：
16. What is the author.s main purpose in writing the passage?A. To show that the motor vehicle is a very dangerous invention.
B. To promote understanding between careless drivers and street walkers.
C To discuss traffic problems and propose possible solutions.
D. To warn drivers of the importance of safe driving.
17. According to the passage, traffic accidents may be regarded as a social problem because_____.
A. automobiles have become most destructive to mankind
B. people usually pay little attention to experts. research
C. civilization brings much harm to people
D. the lack of virtue is becoming more severe
18. Why does the author mention the psychological condition of the driver in Paragraph Three?
A. To give an example of the various reasons for road accidents.
B. To show how important it is for drivers to be emotionally healthy.
C. To show some of the inaccurate estimations by researchers.
D. To illustrate the hidden tensions in the course of driving.
19. Who are NOT mentioned as being responsible for the road accidents?
A. Careless bicycle-riders.
B. Mindless people walking in the street.
C. Irresponsible drivers.
D. Irresponsible manufactures of automobiles.
20. Which of the following best reflects the author.s attitude toward a future without traffic accident problems?
A. Doubtful yet still longing for.
B. Happy and rather confident.
C. Surprise
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