听力原文： So today were gonna talk about animal experimentation. Do you know why animal

experimentation is scientific fraud？ I am an animal lover. Although I have never personally performed vivisection or experimented on animals, I have many friends and former colleagues who have done so. Almost every single one of these people feel an enormous burden and responsibility to see that the animals suffer as little as possible and that no animal in an experiment loses its life for nothing. Scientists for the most part are not in it for the money or the fame, both of which most scientists NEVER see much of, by the way. They want to help make the world a little better while exercising their innate curiosity. For you to demonize the many scientists who experiment while trying to find cures for diseases is really unfortunate and demonstrates that you are terribly uninformed. Am I saying that human life is more important than animal life？ I am not. Animal experimentation is also performed on animals for the betterment of animal health. Am I saying that all animal experimentation is necessary？ Absolutely not. Some of it is very likely a sad waste of animal lives and the cause of needless suffering, and certainly a waste of limited research funding. Am I saying that some of this work has saved human lives？ Absolutely. Satan Jr.s example (insulin) is one such case. As an animal lover, I will be most pleased when the use of animals in science is no longer performed. Do you really want to help make animal experimentation a memory？ Then become a scientist and develop alternative disease models and non-animal based remedies and then make your research widely available to other scientists. If you had really done your homework and focused on something beyond your anger and hatred, you would, see that many scientists have already done just this. You can also donate time and/or money to organizations that support the development of alternatives to animal testing. Science, like so many other fields, is slow to evolve. It will take time. The great advances in science that have given us the high standard of medical care humans and animals enjoy today have come from clinical observation, in vitro research, epidemiology, autopsies, serendipity, computer and mathematical modeling, technology, tissue research using the tissue from the species being studied, molecular biology and genetics, post-marketing drug surveillance, the basic sciences of maths, chemistry and physics and the specialization of medical care, including the specialization of physicians and veterinarians. The animal experimentation lobby, however, spends millions annually to convince the public that all medical advances are directly due to animal experiments. Furthermore, animals are not able to communicate about any side effects they may be experiencing. At least half of the side effects experienced by most drugs cannot be accurately communicated by animals. In April 1998, the Journal of the American Medical Association reported on a study which showed that more than 2 million Americans become seriously ill every year because of toxic reactions to correctly prescribed medicine and 106000 die from those reactions, making drug side effects the sixth most common cause of death in this country! Legal drugs kill more people per year than all illegal drugs combined. People expect me and want me to argue against vivisection on a purely scientific basis. I can do that. However, I cannot and will not forgo the ethical argument. For when all is said and done, I believe that research on animals is ethically wrong, and that nothing "good" can ever come out of something so morally debased. I often cite the hypothermia experiments done on Jews in the concentration camps during World War Ⅱ. This experimentation on helpless, non-consenting humans who suffered and died as a result of these experiments actually taught scientists a great deal about treating hypothermia in humans. But was it right？ I would argue that it was absolutely wrong, no matter how much useful information we garnered.Narrator Listen to part of a lecture in a biology class. Now get ready to answer the questions. You may use your notes to help you answer.

What aspect of animal experimentation does the professor mainly discuss？

A．How harmful it is to animal protection.

B．How useless it is for the medical care.

C．How its development differs from that of others,

D．How it develops from an early ag