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问题 单项选择题

在20世纪50年代初期人们最初发现水俣湾地区出现奇异现象，猫流涎不止、疯癫发狂、步态不稳。后经研究发现这是由于环境污染引起的公害病，称为水俣病。

水俣病的发病机制是

A．氯化甲基汞进入胃内，再吸收入血，与脑细胞的脂类亲和

B．甲基汞在胃内转化为氯化甲基汞，再吸收入血，与脑细胞的脂类亲和

C．甲基汞吸收入血，与脑细胞的脂类亲和，通过胎盘屏障

D．甲基汞吸收入血，与脑细胞的脂类亲和，穿过血-脑脊液屏障

E．与脑细胞的脂类亲和，穿过血-脑脊液屏障，侵犯部位主要在下丘脑

答案

参考答案：B

解析： 此题考查对水俣病的发病机制的理解。水俣病的主要原因是慢性甲基汞中毒。通过食物链途径进入人体的甲基汞在胃酸的作用下才生成氯化甲基汞，继而吸收入血液，可与半胱氨酸结合通过蛋氨酸转运系统透过血-脑脊液屏障，最终进入脑组织。

单项选择题

Most earthquakes occur within the upper 15 miles of the earth’s surface. But earthquakes can and do occur at all depths to about 460 miles. Their number decreases as the depth increases. At about 460 miles one earthquake occurs only every few years. Near the surface earthquakes may run as high as 100 in a month, but the yearly average does not vary much. In comparison with the total number of earthquakes each year, the number of disastrous earthquakes is very small.
The extent of the disaster in an earthquake depends on many factors. If you carefully build a toy house with an erect set, it will still stand no matter how much you shake the table. But if you build a toy house with a pack of cards, a slight shake of the table will make it fall. An earthquake in Agadir, Morocco, was not p enough to be recorded on distant instruments, but it completely destroyed the city. Many per earthquakes have done comparatively little damage. If a building is well constructed and built on solid ground, it will resist an earthquake. Most deaths in earthquakes have been due to faulty building construction or poor building sites. A third and very serious factor is panic. When people rush out into narrow streets, more deaths will result.
The United Nations has played an important part in reducing the damage done by earthquakes. It has sent a team of experts to all countries known to be affected by earthquakes. Working with local geologists and engineers, the experts have studied the nature of the ground and the type of most practical building code for the local area. If followed, these suggestions will make disastrous earthquakes almost a thing of the past.
There is one type of earthquake disaster that little can be done about. This is the disaster caused by seismic sea waves, or tsunamis. (These are often called tidal waves, but the name is incorrect. They have nothing to do with tides.) In certain areas, earthquakes take place beneath the sea. These submarine earthquakes sometimes give rise to seismic sea waves. The waves are not noticeable out at sea because of their long wave length. But when they roll into harbors, they pile up into walls of water 6 to 60 feet high. The Japanese call them "tsunamis", meaning "harbor waves", because they reach a sizable height only in harbors. Tsunamis travel fairly slowly, at speeds up to 500 miles an hour. An adequate warning system is in use to warn all shores likely to be reached by the waves. But this only enables people to leave the threatened shores for higher ground. There is no way to stop the oncoming wave.

The significance of the slow speed of tsunamis is that people may

A．notice them out at sea．

B．find ways to stop them．

C．be warned early enough．

D．develop warning systems．
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单项选择题

对于有心理病态行为的天才人物，哪种看法不是客观中肯的？（）

A、对于这类人，要注意区分他们的正常与不正常状态，他们的伟大成就，也可能是在心理正常的时候创造出来的

B、心理不健康，虽然可以创造，但也是有代价的

C、任何人都会出现心理问题，天才人物也不例外

D、伟大的天才都是心理变态的
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