问题 问答题

        据央视国际报道,近日(2006年3月14日摄),中国科学家率先建成了世界上第一个全超导核聚变“人造太阳”实验装置,模拟太阳产生能量。为了达到聚变所要求的温度,需要用电流产生磁场,电流的强度非常大,时间长了,线圈就要发热。从这个角度来说,装置不可能长时间运转。为了解决这个问题,人们把最新的超导技术引入到该装置中。

        虽然“人造太阳”的奇观在实验室中已经出现,但“人造太阳”所发出的电能在短时间内还不可能进入人们的家中。根据目前世界各国的研究状况,这一梦想最快有可能在50年后实现。

        “人造太阳”的实验研究具有十分重大的战略意义。在过去的100年中,人类对能源的研究和使用已从化石燃料的单一化结构,发展到以化石能源为主,核能和水能互补的多元格局。但是,石油、煤炭等化石能源不可再生,目前已经商业化的核裂变能又会产生一定的核废料,同时受到原料的限制。

        而核聚变能则被认为是无限、清洁、安全的换代新能源。据专家介绍,自然界最容易实现的聚变反应是氢的同位素——氘和氚的聚变。氘在地球的海水中藏量丰富,多达40万亿吨,如果全部用于聚变反应,释放出的能量足够人类使用几百亿年,而且反应产物是无放射性污染的氦。这就是为什么世界各国,尤其是发达国家不遗余力,竞相研究、开发核聚能的原因所在。

问:

(1)在“人造太阳”中,为什么要用到超导材料?

(2)这个装置和氢弹的原理有何相同点和不同点?

(3)核聚变的优势有哪些?(写出两点)

答案

(1)用超导材料导线不会发热,电流可以很大,设备也可以长时间运行。

(2)相同点:都是核聚变;不同点:氢弹是不可控聚变,“人造太阳”是可控聚变。

(3)清洁,无污染;原料含量丰富。

单项选择题
阅读理解

阅读理解。

     When his young son was ill, Mr Wei took him to a clinic (诊所). They were the first of the day and did

not have to wait long. The nurse took the boy into the doctor's room while Mr Wei waited outside. After a

few minutes, the doctor came out of his room and spoke to the nurse.

     "Have we got a screwdriver (螺丝刀)?" he asked her. The nurse looked in a drawer (抽屉) and found a

screwdriver. She gave it to the doctor and he went back into his room.

     A few minutes later he came out again. "I need a saw (锯)," he said to the nurse this time. Again the nurse

looked in the drawer. She found a saw and gave it to the doctor. He went back into his room.

     A few minutes later the doctor came out of his room for the third time. "I'm going to need a hammer," he

said. For the third time the nurse looked in the drawer. Shp found a hammer and gave it to the doctor.

     This time, Mr. Wei could not keep quiet." Excuse me," he said:"but what is wrong with my son? And what

are you doing to him?"

     "I haven't examined him yet," the doctor said. "I'm still trying to get my hag open."

1. Mr. Wei's son was _____. [ ]

A. waiting in a queue

B. angry about his waiting

C. impatient (不耐烦) to get in to see the doctor

D. the first person to be seen by the doctor

2. The doctor came out to _____. [ ]

A. ask for some tools

B. shout at the nurse

C. look in the drawer

D. explain something to Mr. Wei

3. The underlined word "hammer" in the 4th paragraph means _____. [ ]

A. a kind of medicine

B. a piece of medical equipment

C. a kind of everyday tool

D. a piece of furniture

4. At last, Mr. Wei _____. [ ]

A. offered to help the doctor get his bag open

B. wanted to be there when his son was examined

C. was worried about his son

D. helped the nurse look for the hammer

5. Which would be the best title for this passage? [ ]

A. Mr. Wei and His Son

B. The Doctor's Job

C. The Right Tools for the Bag

D. A New Way to Treat Patients