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问题 单项选择题

土壤对重金属的环境容量是指

A．重金属溶解在土壤中的最大值

B．土壤中重金属不对农作物产生危害的最大值

C．土壤中重金属能对农作物产生危害的最小值

D．土壤中重金属的实际含量

E．土壤中重金属的背景值

答案

参考答案：B

解析： 土壤对某污染物的环境容量是指一定环境单元、一定时间内、在不超过土壤卫生标准的前提下土壤对该污染物能够容纳的最大负荷量；土壤卫生标准是指土壤中有害物质的最高容许浓度，因此土壤对重金属的环境容量可以理解为土壤中重金属不对农作物产生危害的最大值。

单项选择题

在一个大型组织的会计部门，CD—ROM最有可能被用来：（）

A.提供EDI交易的永久审计线索。

B.保存该部门收到的文件的图像。

C.记录从银行退回的支票正面和背书。

D.提供一个检索会计标准和指南的途径。
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单项选择题

My First Experience with AIDS Patients
我初次接触艾滋病人


by Marc Kielburger
I was ushered to the AIDS ward of a hospice in the slum.I would later learn that the ward did not exist，at least not officially.Not a single person in Thailand had AIDS，according to the Thai government at the time.People got"sick，"of course，sometimes"very sick."but no one had AIDS.The hospice was home to an ever-growing number of"very sick"people.
I entered the ward and was greeted by two Thai nurses.
"Thank goodness you are here，Marc，"said the first.
"You’re a doctor，right"
I shook my head.
"So you are a medical student then!"
I shook my head again.
"But you know medicine，right"
"Kinda，"I offered."I watch E.R.,every Thursday"
After a rapid exchange in Thai，the first one said，"NO problem.Get ready for your fou- hour medical school training!"
"But in my country medical school takes years!" I protested.
"We don’t have that long," she replied. "So we better get started. "
During the next few hours, I learned to clean wounds, administer IVs, treat bedsores, and dispense medicine. The work was punishing, made worse by stifling heat, frequent blackouts, and an incredible stench in the air. I tried desperately to hide my weak nerves and queasy stomach, but more than once dashed for the bathroom to throw up.
Just when it seemed my training was coming to an end, the nurse took me aside. "There are only two more things you need to know," she said. "On the left-hand side of the ward, you will find what we call the Exit Area. " As it turned out, she meant "exit" in the largest sense of the word. Terminally ill patients were hidden behind a curtain and then exited out of the ward after death. "The second thing you need to know," she continued, "is that we haven’t had a day off in three weeks. You’ll be looking after the ward by yourself for the next shift. "
My jaw dropped.
"Don’t worry, Mare," said the other nurse, patting me on the shoulder before turning to leave. "Think of this as the beginning of your residency !" And with that, they walked out. Alone and petrified, I tried unsuccessfully to keep calm.
I counted to twenty-four. That’s how many AIDS patients were in my charge. What am I going to do I thought. What can I do I fell back on my training with the Canadian government and put my talents to work. I served patients water-some with ice, some without. Next, I tried to cheer up everyone, myself included, giving enthusiastic high-fives to patient after patient. Soon enough, everyone was laughing. Some were laughing with me, others most definitely at me, but I didn’t care. As long as I could keep people smiling, I was sure it would all be fine. And it was. Until a short while later, when a patient in the Exit Area began to choke. He had fluid in his lungs and could not breathe. As I crossed the floor, I could hear the man gasping for air. Fumbling and scared, I pulled back the curtain and administered the medicine the nurses had recommended. The man didn’t respond. With nothing left to offer, I sat down and held his hand, looking into his eyes as he breathed heavily for a while and then stopped. Watching him slip away, I was hit by a feeling of anguish such as I’d never felt, either before or since. It haunts me to this day.

Why were the two Thai nurses happy to see Marc

A．Because Marc was an experienced doctor for AIDS.
B．Because Marc could amuse the patients.
C．Because Marc would offer them further medical training.
D．Because Marc would work in the ward so that they could enjoy a day off.
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