问题 单项选择题

关于汞中毒,以下说法正确的是

A.汞为灰白色质软的重金属

B.可溶于水

C.人类在正常的生活中接触不到汞及其化合物

D.尿汞阳性是诊断急性汞中毒早期的重要指标

E.汞的无机化合物主要是通过消化道侵入人体

答案

参考答案:E

解析:

汞为银白色的液态金属,常温中即有蒸发。汞中毒以慢性为多见,主要发生在生产活动中,长期吸入汞蒸气和汞化合物粉尘所致。以精神一神经异常、齿龈炎、震颤为主要症状。大剂量汞蒸气吸入或汞化合物摄入即发生急性汞中毒。对汞过敏者,即使局部涂抹汞油基质制剂,亦可发生中毒。急性汞中毒主要由口服升汞等汞化合物引起,慢性汞中毒常为职业性吸入汞蒸气所致。

单项选择题

For some people, the light of human attention has an unbearable brilliance. Like ivy along the dim edge of a garden, they prefer the social shadows, shunning parties, publicity and fame of any sort. Then there are the flowers of the human arboretum. For them, being in the view of others seems necessary for life itself. From Hollywood to fabricated prime-time reality, this spotlight-dependent species is thriving.
But what about the individuals who crave attention for more desperate reasons Those who resort to unusual ways to get it Lately, it seems, a dark bloom of these characters has emerged. For motives known only to themselves, they have won notoriety by drawing on an almost sacred well of social status: victim hood.
In early April, US national news outlets tracked the disappearance of Audrey Seiler, a sophomore at the University of Wisconsin in Madison. Police and hundreds of concerned citizens searched for four days before Seiler was discovered. Seiler said she was kidnapped. Within hours, however, her story fell apart. Police announced that her abduction had been a hoax. Why would a popular student make herself disappear Her motive remains a mystery, but perhaps it had something to do with the search parties and the news bulletins that surrounded her.
Sympathy is a powerful sentiment that can connect complete strangers. But if it’s used to manipulate, the backlash can be much more intense.
In February, a Waterbury, Connecticut, man was arrested as a result of exploiting sympathy. Edward Valentin told reporters that he had received word that his wife, serving in Iraq, had been killed in an explosion. Police said Valentin admitted the fabrication, reasoning that if people felt sorry for him maybe the military would send his wife home. Evidence, however, points elsewhere.
In its extreme form, such a craving shows up in mental disorders, where sufferers may seek attention by causing themselves harm. But even when it comes with no diagnosis, a deep craving to be noticed can have a wide impact.
For these individuals, victim hood represents a "pure state of guilt-free entitlement," said psychologist Richard Levak, of Del Mar, California. "They go from being utterly deprived to being utterly indulged. In today’s world ... people have become more depressed and disconnected from each other. So you get people who crave affection and attention and approval. They don’t know how to ask for it and they don’t know how to get it. That leaves them vulnerable," Levak said.

According to the first paragraph, some people ______.

A.do not like to be in the spotlight

B.like the dark side of society

C.prefer the beauty of plants to people

D.avoid the media but enjoy parties

单项选择题