电流截止负反馈是一种只在调速系统主电路过电流下起负反馈调节作用的环节，用来限制主回路

患者，男，20岁。肌注青霉素后突然晕倒，血压测不到。应首先采取的抢救措施是（）。

A.立即静脉点滴呋塞米（速尿）

B.静脉点滴5%碳酸氢钠

C.立即皮下注射肾上腺素

D.静脉注射问烃胺

E.静脉点滴20%甘露醇

Leber遗传性视神经病是一种遗传病，此病是由线粒体DNA基因突变所致。乔女士的母亲患有此病，如果乔女士结婚生育，下列预测正确的是[ ]

A．如果生男孩，孩子不会有致病基因

B．如果生女孩，孩子不会有致病基因

C．不管生男孩或生女孩，孩子都会有致病基因

D．必须经过基因检测才能确定，但不能通过推论来确定

魔幻现实主义指的是20世纪中期拉丁美洲小说创作中的一个流派，下列属于魔幻现实主义代表作品的是（）。

A.《百年孤独》

B.《红与黑》

C.《玩偶之家》

D.《尤利西斯》

Language belongs to each member of the society, to the cleaner （） to the professor.

A．as far as

B．the same as

C．as much as

D．as long as

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.