内伤腰痛的证候特征是（） A.起病缓慢 B.腰痛绵绵 C.时作时止 D.遇劳加剧 E

漫画《Q版人生》启示我们（   ）

A．量变必然导致质变

B．要不失时机促成质变

C．事物发展是前进性和曲折性的统一

D．挫折比成功更重要

从实际情况看，目前我国房地产经纪业务主要集中在新建商品房市场和（）。

A.存量房市场

B.土地市场

C.房屋租赁市场

D.房屋买卖市场

制备煎膏剂用

A．浸渍法
B．煎煮法
C．渗滤法
D．回流法
E．水蒸汽蒸馏法

作为现代意义上的社会保障法只有在承认和尊重国民的（）时代才可能出现。

A、国民基本发展权；

B、国民基本教育权；

C、国民基本财产权；

D、国民基本生存权。

Believe it or not，optical illusion can cut highway crashes.
Japan is a case in point．It has reduced automobile crashes on some roads by Rearly 75 percent using a simple optical illusion．Butst．ripes,called chevrons(人字形)，painted on ther rads make drivers think that they are driving faster than they really are，and thus drivers slow down.
Now the American Automobile Association Foundation for Traffic Safety in Washington D．C. is planning t。repeat Japan’s success．Starting next year，the foundati。n will paint cheyrons and。ther pattems of stripes on selected roads around the country to test how well the patterns reduce highway erashes．
Excessive(too great)speed plays a major 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(danger)are the greatest curves，exit slopes，traffic circles，and bridges．
Some studies suggest that straight，horizontal bars painted across roads can initially cut the average speed of drivers in half．However,traffic。ften returns to full speed within months as driVers become used to seeing the painted bars．
Chevrons，scientists say，not only give drivers the impression that they are driving faster than they reallv are but als0 make a lane appear to be narrower．The result is a longer lasting reduction in highway speed and the number of traffic accidents．

What does the author say about straight,horizontal bars painted across roads

A. They are suitable only on broad roads.
B. They are falling out of use in the United States.
C. They are ignored in a long period of time.
D. They cannot be used successfully to traffic circles.