在可能导致胎儿发生唇腭裂畸形的药物中，不包括（）。 A.强心药物 B.抗肿瘤药物 C

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．

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 look more attractive

D. will have a longer effect on drivers

在WWW服务中，统一资源定位器URL由3部分组成： 【1】 、主机域名与文件名。

可比实例选取得恰当与否，直接影响到市场法评估出的价格的准确性。 ( )

伯里克利在《论雅典之所以伟大》的演讲中说：“这是雅典人与众不同的优点，行动时我们勇气百倍，行动前却要就各项措施的利弊展开辩论。”文中的“雅典人”是指（）

A.除贵族外的雅典所有公民

B.除外邦人以外的全体雅典人

C.除第四等级外的所有雅典公民

D.可参加公民大会的所有雅典人

材料一美国1787年宪法“是迄今为止，在特定的历史时期人类智慧和意志所创造出的最

美妙的杰作”。

——英国政治家威廉.格莱斯顿

材料二“我们的宪法之所以恒久，就在于它简洁。它是一块奠基石，而不是一座完整的大

厦，或者用句老话比喻：它是根，而不是完美的藤。”

——美国总统威尔逊

材料三“一个向上帝要求赋予自由的民族，没有迈出同时给予非洲人自由的第一步是不应

该的。”

——美国黑人领袖马丁.路德.金

结合1787年宪法的内容说明，为什么说“它是根，而不是完美的藤”？