什么是社会理想？在我国，社会理想包括哪两个层面的内容？

颈内动脉系统TIA最常见的症状? 特征性症状?

(三)

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 nearly 75 percent using a simple optical illusion. But stripes, called chevrons, painted on the roads 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 to repeat 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(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 often 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 really are but also make a lane appear to be narrower. The result is a longer lasting reduction in highway speed and the number of traffic accidents.

The passage mainly discusses（）.

A．a new way of highway speed control

B．a new pattern for painting highways

C．a new way of training drivers

D．a new type of optical illusion

汇兑一般用于同城范围或同一票据交换区域内的结算，异地间的结算不使用汇兑结算。()

男，8岁，步行摇摆，起立困难，进行性加重已二年。体检可见有肩胛带肌萎缩，腓肠肌假肥大。其兄15岁有类似发病情况，现已卧床不起，其姐18岁，现正常。（）

A.补钾疗法

B.支持疗法

C.气管切开术

D.人工辅助呼吸

E.新斯的明

F.普鲁卡因酰胺

G.苯妥英钠

有一例蛛网膜下腔出血患者，哪项检查对其无帮助

A．头颅CT
B．ECT
C．MRI
D．核磁血管成像
E．全脑血管造影