发布时间 : 星期六 文章新视野大学英语视听说教程第二版4Unit8答案更新完毕开始阅读7db39791b8f67c1cfad6b8d7
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Question 1
W: I think all GM foods should be labeled, so we can make intelligent choices
about whether to eat them. M: We're already eating a lot of GM food without knowing it. It has quietly
become a part of our reality. Q: What do we learn about the man from the dialog?
Question 2
M: Mary, I hear that many scientists are devoted to human organ clones in
the hope of replacing malfunctioning organs to make people live better and longer. I think that's desirable. W: Well, Mike, I don't think so. Since illness and death are natural processes
of life, we should obey nature's rules. Q: Which of the following is true according to the dialog?
Question 3
M: I have a meeting this afternoon, and I'm supposed to pick up the children
from school at the same time. I need another one of me. W: There's a new movie called Multiplicity where a company clones copies of
people. Believe me, you don't want that. One of you is more than enough. Q: What does the woman mean? Question 4
W: I've chosen Mr. Green's The Secret of Cloning as my elective this semester. M: Wow, fantastic! I'm excited that we share something in common at last.
I'd like to learn some knowledge on genes and cells, what about you? Q: What can we infer from the dialog? Question 5
W: I'm worried about the safety of GM foods. I strongly suggest consumers
be informed of the ingredients of all the food. M: Don't suffer from imaginary fears. We have no evidence that GM foods can
definitely harm our health. But we do know foods with chemicals can. Q: Which of the following is true according to the dialog?
Script
There are many ways in which human stem cells can be used in basic research and in clinical research.
Studies of human stem cells may yield information about the complex events that occur during human development. A primary goal of this work is to identify how stem cells become divided or differentiated. Scientists know that turning genes on and off is central to this process. Some of the most
serious medical conditions, such as cancer and birth defects, are due to abnormal cell division and differentiation. A better understanding of the
genetic and molecular controls of these processes may yield information about how such diseases arise and suggest new strategies for therapy. A significant barrier to this use and most uses of stem cells is that
scientists do not yet fully understand the signals that turn specific genes on and off to influence the differentiation of the stem cell. The most important potential application of human stem cells is perhaps the
generation of cells and tissues that could be used for cell-based therapies. Today, donated organs and tissues are often used to replace ailing or destroyed tissue, but the need for transplantable tissues and organs far outweighs the available supply. Stem cells, directed to differentiate into specific cell types, will offer a source of replacement cells and tissues to treat diseases including Parkinson's and Alzheimer's diseases, spinal cord injury, stroke, burns, heart disease and diabetes.
For example, it may become possible to generate healthy heart muscle cells in the laboratory and then transplant those cells into patients with chronic
heart disease.
Script
Genes are the parts of cells that control the growth of living things, including people. Now, a company in Iceland is working to create the most
detailed map yet of all known human genes.
Doctor Karl Stefansson, head of the company, believes that the people of Iceland present a special chance to study the human genome and how some genes cause disease. Iceland has a very small population—about 280,000 people. The majority of the population shares a small group of common ancestors who lived thousands of years ago. The people of Iceland keep extensive records of their ancestors. In addition, Iceland has an excellent healthcare system. Doctor Stefansson says his researchers are studying genetic diseases in many families over hundreds of years.
So far, researchers have examined the genes of at least 146 families. The Iceland genome project is using a much larger group of individuals to observe differences in human genes than any other project. For example, American scientists made a genetic map based on only eight large families in France. Human beings have almost exactly the same genes. Small genetic differences make us look different from each other. These differences can also make us
more likely to get some diseases.
The company's main project is to identify genes that cause disease. Scientists believe most common diseases are caused by several abnormal genes working together. The company claims to have already found three disease-causing genes, linking to a mental disease and two kinds of strokes.