专业英语四级听力-51
(总分：100.00，做题时间：90分钟)
一、{{B}}PART Ⅰ DICTATION{{/B}}(总题数：1，分数：40.00)
1.Listen to the following passage. Altogether the passage will be read to you four times. During the first reading, which will be done at normal speed, listen and try to understand the meaning. For the second and third readings, the passage will be read sentence by sentence, or phrase by phrase, with intervals of 15 seconds. The last reading will be read at normal speed again and during this time you should check your work. You will then be given 2 minutes to check through your work once more.
Life Span

（分数：40.00）
__________________________________________________________________________________________
正确答案：()
解析：[听力原文]
Life Span

About a century ago, /the average life span for Americans was about 50 years. /Today, the typical American lives for around seventy-eight years. /According to a German aging study, /the maximum life span in industrialized countries has increased by two years every decade /since the mid-19th century. /What accounts for such increased longevity? /Between 1900 and 1950, /inventions such as refrigeration and sewage treatment meant that/young people were able to survive longer. /Moreover, medical breakthroughs helped contain diseases/such as some fatal ones that killed many children. /These advances helped increase the average life span. /Medical discoveries after World War II tended to benefit older people. /Treatments for heart disease, /for example, have allowed the elderly t
o live longer on average. /This means that future medical breakthroughs will result in even longer average life span./

[解析] 这篇听写有一定的难度，整体上句子比较长且多为复合句。不过，在理解大意的基础上如果能迅速地把握关键词life span，就基本能判断文章的主要内容：即随着科学技术日新月异的发展，许多曾影响人类寿命的疾病得到根治，因此人类的寿命大大地延长了。另外，account for是个关键性词组，听懂并快速理解这个词组对把握下面有关人类寿命延长的原因至关重要。此外，要注意refrigeration这个词的拼写。
二、{{B}}PART Ⅱ LISTENING COMPREHENSION{{/B}}(总题数：0，分数：0.00)
三、{{B}}SECTION A CONVERSATIONS{{/B}}(总题数：3，分数：20.00)
In this section you will hear several conversations. Listen to the conversations carefully and then answer the questions that follow.
Questions 1 to 3 are based on the following conversation. At the end of the conversation, you will be given 15 seconds to answer the questions.
Now listen to the conversation.
In this section you will hear several conversations. Listen to the conversations carefully and then answer the questions that follow.
Questions 1 to 3 are based on the following conversation. At the end of the conversation, you will be given 15 seconds to answer the questions.
Now listen to the conversation.
（分数：6.00）
(1).Why does the woman tell the man the story?
∙ A. To inform him about a class he missed.
∙ B. Because he is eating fish sticks.
∙ C. Because she tutors him.
∙ 四级听力D. To encourage him to eat a healthier lunch.
（分数：2.00）
 A.
 B. √
 C.
 D.
解析：[听力原文] W: {{U}}I see you are having the fish for lunch.{{/U}} M: That's right. Fish sticks and tomato soup, my favorites. W: I bet they were frozen. M: What? W: The fish sticks. M: Of course they were frozen. We are hundreds of miles from the Ocean. The cafeteria can't afford to fly in fresh fish. W: I just mentioned it because an anecdote Professor Chambers told me in my American social history class this morning. M: He talked about fish sticks? W: Not exactly. But he did talk about frozen fish. OK, this is back in 1912, right? It's 20 degrees below zero. And this guy Clarence Birdseye's out ice-fishing. M: Where is this, Antarctica? W: No. Massachusetts I think. Anyway he catches a fish and dro
ps it beside him on the ice and it freezes solid. M: So? W: So, {{U}}later at home he thaws out the fish in a bucket of water and it's alive. Of course Birdseye is amazed.{{/U}} But he eventually figures out that the fish froze so fast that no large ice crystals formed. M: What do you mean? W: {{U}}Look, usually when a plant or animal cell freezes, large ice crystals form inside and eventually tear the cell wails. That's what kills the frozen plant or animal. And also what changes the taste of something that's been frozen. But if you freeze something quickly, only very small ice crystals form.{{/U}} So Birdseye invented the process of quick freezing food. M: And that was the beginning of frozen foods? W: Right. [解析] 本题考查原因。根据原文划线部分可知，两人的对话从这个男士正在吃的鱼排展开，谈到了女士的美国社会史教授讲述的冷冻食品的来源。因此B为正确答案。
(2).Why is it important to quick freeze fresh food?
∙ A. The cells of plants and animals are damaged by slow freezing.
∙ B. It saves time in the food production process.
∙ C. It reduces the amount of energy required to freeze the food.
∙ D. The food defrosts more quickly.
（分数：2.00）
 A. √
 B.
 C.
 D.
解析：[解析] 本题考查原因。根据原文划线部分可知，快速冷冻可以避免慢速冷冻带来的弊端。因此A为正确答案。
(3).What was Clarence Birdseye surprised to learn?
∙ A. A fish could survive being frozen.
∙ B. The fish were easier to catch in the winter.
∙ C. Food can be kept frozen indefinitely.
∙ D. Solutions that freeze slowly form large crystals.
（分数：2.00）
 A. √
 B.
 C.
 D.
解析：[解析] 本题考查事实。根据原文划线部分可知，令Birdseye惊奇的是鱼居然还活着。故A为正确答案。
Questions 4 to 6 are based on the following conversation. At the end of the conversation, you will be given 15 seconds to answer the questions.
Now listen to the conversation.
Questions 4 to 6 are based on the following conversation. At the end of the conversation, you will be given 15 seconds to answer the questions.
Now listen to the conversation.
（分数：6.00）
(1).What happened after the man built his first computer?
∙ A. He turned to become an enthusiastic reader.
∙ B. He went on to build a machine for his Junior High School.
∙ C. He became obsessed with computer engineering.
∙ D. He was brushed by a hook.
（分数：2.00）
 A.
 B.
 C. √
 D.
解析：[听力原文] W: What started you in computers? M: I built my first computer when I was in Junior High School. I was an enthusiastic reader, I studied everything I could get my hands on. {{U}}Then I turned to building my own machine. From that point on, I was hooked.{{/U}} W: Where do you see computers as going in the future? M: {{U}}This will be the era of distributed devices,{{/U}} some of which will be in your walls, some of which you will wear, some of which will be in your cars and throughout your house, and maybe one of which will be on your desk. Devices with processors in them will be everywhere, they will be connected, and they will look less like traditional PCs. W: What kind of computer do you have now? M: My primary machine is a heavily loaded PowerMac, which I use to write all my books and to do video editing. I've also got a Toshiba notebook which I use for all my work at the company and for email. W: There are critics who say that technology is danger
ous and is moving too fast. What's your reaction? M: {{U}}There is criticism voiced in every generation.{{/U}} One can't stop this kind of progress, so the critics you cite above are cursing the dark. That being said, {{U}}it's important to always consider the implications of the technology we create, for they have social impact.{{/U}} [解析] 本题考查事实。根据原文划线部分可知，这里使用了hook“钩住”一词，因此C为正确答案。