问题 单项选择题

  核电站的一次性投资确实比火电站大一些。衡量电站的经济价值,还要核算电站运行后消耗的燃料、设备折旧、运行管理等费用。30年来,国际上对煤电成本与核电成本所作的等值比较,显示出修火电站实际出现的低投入经济效应的负走向,修建核电站则正相反。目前,已有几十个国家建成300余座核电站,总功率达2亿千瓦左右,绝大多数核电站已使核电成本降至煤电的60%左右。现代经济价值观取得了又一次胜利。

  至于核电站所出现的事故,不足以否定其安全性。从核反应形式看,原子弹可以和核电站类比,但原子弹所用的铀-225浓度在弹体中高达90%,因此造成核链式反应的不可控性;而核电站采用的燃料是浓度低于4%的铀-235,这样反应效应就与原子弹有有根本的区别。从实际情况看,任何形式的电站,只要设计、管理出了问题,都可能导致事故发生。1979年印度一座大坝水电站爆炸竟使1.5万人丧生,当然这不是说切尔诺贝利核电站核物质外泄夺走了人的生命就值得庆幸。值得庆幸的是核电站系统工程技术有了新突破,核电站安全保险系数优于火电站。说到环境保护,最先进的火电站也难以让人作乐观的承诺,而核电站则别具优势。

“与原子弹有了根本的区别”的含义是()。

A.核电站具有可控性,原子弹具有不可控性

B.核电站的核链式反而具有可控性,而原子弹的核链式反应是不可控的

C.核电站采用燃料铀-235的浓度低于4%,不会出现不可控性核链式反应

D.核电站采用的铀-235浓度远远低于原子弹中的核物质浓度,已不具有危险性

答案

参考答案:B

阅读理解

阅读理解。

     It was Sunday. I had one last patient to see. I approached her room in a hurry and stood at the doorway.

She was an older woman, sitting at the edge of the bed, struggling to put socks on her swollen (肿胀的) feet.

I entered, spoke quickly to the nurse, and examined her chart. She was getting better.

     I looked down at her. She asked if I could help put on her socks. Instead, I said something like this."How

are you feeling? Your sugars "and blood pressure were high but they're better today. The nurse mentioned you

were anxious to see your son who's visiting you today. I bet you really look forward to seeing him."

     She Stopped me with a serious voice, as if she was giving an order."Sit down, Doctor. This is my story,

not your story."

     I was surprised and embarrassed. I sat down. I helped her with the socks. She began to tell me that her only

son lived around the corner from her, but she had not seen him in five years. She believed that her health proble

ms really had something to do with it. After hearing her story and putting on her socks, I asked if there was

anything else I could do for her. She shook her head and smiled. All she wanted me to do was to listen.

     Later on, I often thought of what that woman taught me. Everyone has a story and each story is different.

Some have a beginning, middle and end. Others wander without a clear conclusion. Yet all those things do not

really matter. What matters to the storyteller is that the story is heard-without interruption or judgment.

1. The writer went to visit the older woman to _____.

A. listen to her story

B. tell her good news

C. help her put on her socks

D. see if she was getting better

2. What problem did the older woman have?

A. She ate too much sugar.

B. She had high blood pressure.

C. She had too many visits.

D. She liked telling others stories.

3. The underlined word "it" in Paragraph 4 refers to the older woman's _____. 

A. not having seen her son for long

B. having no one to look after her

C. serious voice when giving orders

D. struggling to put socks on her feet

4. According to the text, we know that the writer was _____.

A. serious

B. honest

C. patient

D. humourous

5. What does the story mainly tell us?

A. Everyone should learn to listen to others.

B. Children had better stay with their parents.

C. We all have a story and each one is different.

D. Older women are good at telling their stories.

问答题 简答题