46. The author begins his article with Edmund Burke's words to

　　[A] call on scientists to take some actions.

　　[B] criticize the misguided cause of animal rights.

　　[C] warn of the doom of biomedical research.

　　[D] show the triumph of the animal rights movement.

　　47. Misled people tend to think that using an animal in research is

　　[A] cruel but natural.

　　[B] inhuman and unacceptable.

　　[C] inevitable but vicious.

　　[D] pointless and wasteful.

　　48. The example of the grandmotherly woman is used to show the public's

　　[A] discontent with animal research.

　　[B] ignorance about medical science.

　　[C] indifference to epidemics.

　　[D] anxiety about animal rights.

　　49. The author believes that, in face of the challenge from animal rights advocates, scientists should

　　[A] communicate more with the public

　　[B] employ hi-tech means in research.

　　[C] feel no shame for their cause.

　　[D] strive to develop new cures.

　　50. From the text we learn that Stephen Cooper is

　　[A] a well-known humanist.

　　[B] a medical practitioner.

　　[C] an enthusiast in animal rights.

　　[D] a supporter of animal research.