题目内容
Gene therapy and gene-based drugs are two ways we could benefit from our growing mastery of genetic science. But there will be others as well. Here is one of tile remarkable therapies on the cutting edge of genetic research that could make their way into mainstream medicine in the coming years.While it’s true that just about every cell in the body has the instructions to make a complete human, most of those instructions are inactivated, and with good reason: the last thing you want for your brain cells is to start churning out stomach acid or your nose to turn into a kidney. The only time cells truly have the potential to turn into any and all body parts is very early in a pregnancy, when so called stem cells haven’t begun to specialize.Yet this untapped potential could be a terrific boon to medicine. Most diseases involve the death of healthy cells -- brain cells in Alzheimer’s, cardiac cells in heart disease, pancreatic cells in diabetes, to name a few; if doctors could isolate stem cells, then direct their growth, they might be able to furnish patients with healthy replacement tissues.It was incredibly difficult, but last fall scientists at the University of Wisconsin managed to isolate stem cells and get them to grow into neural, gut, muscle and bone cells. The process still can’t be controlled, and may have unforeseen limitations; but if efforts to understand and master stem-cell development prove successful, doctors will have a therapeutic tool of incredible power.The same applies to cloning, which is really just the other side of the coin; true cloning, as first shown with the sheep Dolly several years ago, involves taking a developed cell and reactivating the genome within, resetting its developmental instructions to a pristine state. Once that happens, the rejuvenated cell can develop into a full fledged animal, genetically identical to its parent.For agriculture, in which purely physical characteristics like milk production in a cow or low fat in a hog have real market value, biological carbon copies could become routine within a few years. This past year scientists have done for mice and cows what Ian Wilmut did for Dolly, and other creatures are bound to join the cloned menagerie in the coming year.Human cloning, on the other hand, may be technically feasible but legally and emotionally more difficult. Still, one day it will happen. The ability to reset body cells to a pristine, undeveloped state could give doctors exactly the same advantages they would get from stem cells: the potential to make healthy body tissues of all sorts, and thus to Cure diseases. That could prove to be a true "miracle cure". Which of the following is true according to the text().
查看答案
搜索结果不匹配？点我反馈
更多问题
Miss Wang has met Professor Kennedy before.
W: Hi! Paul. All set for your speech club presentation this eveningM: Yes, I’m going to discuss robots.W: Robots You mean, those machines that walk and talk like in the moviesM: No, industrial robots, like those used in the automotive and electronics industries.W: I saw an article about that kind of robot the other day. There were pictures of robots welding cars, but they certainly didn’t look the way I thought robots should look.M: The robots we usually imagine are made up in science fiction. In industry, robots are designed to do a specific set of operations such as welding car frames. They are rarely built to resemble humans.W: Actually, all they need is a kind of brain to give signals and a mechanism such as an arm to carry out instructions, rightM: Right! Tiny computers become the brains of these robots. The computer sends signals in the form of electrical impulses that move an arm and a claw. The claw is the hand that does a particular kind of work. Some new industrial robots can reach to a number of tasks and it’s easy to reprogram them to perform totally different operations. That’s one reason why they’re becoming so popular.W: They increase productivity, don’t they I mean that even though they’re still quite expensive, they often cost less time doing the same job. I imagine robot will be used more and more.M: Exactly. So now that you know all about the next industrial revolution, you don’t have to come to speech club tonight. According to the woman, why are robots becoming more widely used().
It is time the authorities concerned ______(采取适当措施来解决交通问题).
At some time in your life, you may have a strong desire to do something strange or terrible. However, chances are that you don’t act on your impulse, but let it pass instead. You know that to commit the action is wrong in some way and that other people will not accept your behavior. Perhaps the most interesting thing about the phenomenon of taboo behavior is how it can change over the years within the same society, how certain behavior and attitude once considered taboo can become perfectly acceptable and natural at another point in time. Topics such as death, for example, were once considered so upsetting and unpleasant that it was a taboo to even talk about them. Now with the publication of important books such as On Death and Dying and Learning to Say Goodbye, people have become more aware of the importance of expressing feelings about death and, as a result, are more willing to tall about this taboo subject. One of the newest taboos in American society is the topic of fat. Unlike many other taboos, fat is a topic that Americans tall about constantly. It’s not taboo to talk about fat; it’s taboo to be fat. The "in" look is thin, not fat. In the work world, most companies prefer youthful-looking, trim executives to sell their images as well as their products to the public. The thin look is associated with youth, vigor, and success. The fat person, on the other hand, is thought of as lazy and lacking in energy, self- discipline, and self-respect. In an image-conscious society like the U.S., thin is "in", fat is "out". It’s not surprising, then, that millions of Americans have been obsessed with staying slim and "in shape". The pursuit of a youthful physical appearance is not, however, the sole reason for Americans’ fascination with diet and exercise. Recent research has shown the critical importance of diet and exercise for personal health. As in most technologically developed nations, the life style of North Americans has changed dramatically during the course of the last century. modern machines do all the physical labor that people were once forced to do by hand. Cars and buses transport us quickly from point to point. As a result of inactivity and disuse, people’s bodies can easily become weak and vulnerable to disease. In an effort to avoid such a fate, millions of Americans are spending more of their time exercising. From the passage we can infer taboo is ______.
微信支付 
支付宝支付