题目

右图所示，甲：用锡箔小帽套在胚芽鞘外面，单侧照光；乙：除去芽尖，把含有生长素的琼脂小块放在切面右侧，再单侧照光，则甲、乙分别将（    ） A．向土直立生长，不弯曲生长 B．向上直立生长，向右侧弯曲生长 C．向上直立生长，向左侧弯曲生长 D．停止生长，向右侧弯曲生长 答案：C    A recent announcement by scientists that they have successfully cloned the first human embryo has caused much debate and has shocked many people around the world. On the one hand，some scientists point out that if you clone an embryo，you can produce valuable tissues(组织）and organs that could be used to save human lives. On the other hand，many people，including some scientists, disagree and fear that if mankind interferes with（干涉）nature in this way，they may be on their way to producing a real-life Frankenstein’s monster.     Cloning is producing an exact copy of a plant or an animal using its cells. The first mammal to be cloned successfully from an adult cell was Dolly the sheep. She was born in 1996 and died in early 2003，at a much younger age than normal. When she was born，many people were angry because they thought cloning would create more disease in the animal world. However，in general the scientists were praised for their wonderful scientific breakthrough.     The Scottish scientist who created Dolly，Ian Wilmut，is shocked that some scientists are now considering cloning human beings. Although he researches cloning，his intention has never been to create copies of humans. Instead，he thinks research efforts should concentrate on creating new tissues and organs that could eventually be used to cure diseases like cancer. However，some people consider that cloning human embryos with the intention of destroying them shows no respect for human life.     While cloning human embryos is illegal in many countries，some scientists are already pushing ahead with research so as to deliver a cloned human baby. Severino Antinori，an Italian doctor，is one of the leaders in this kind of research. He has declared that he wants to be the first to clone a human being.     In China，scientists have focused their efforts on cloning animals，as well as stern cells to be used in medical research. China has succeeded in producing clones of cows and goats，and continues to research ways in which cloning can benefit mankind. 51. Which of the following statements about cloning is TRUE according to the passage? A. Cloning technology can only be applied to animals. B. A cloned animal can live longer than a normal one. C. People all over the world are happy about the birth of Dolly. D. Cloning can produce valuable tissues and organs to cure human diseases. 52. The reasons why people are anti-cloning include the following EXCEPT that_______. A. cloning may produce a real-life Frankenstein’s monster B. cloning might create more disease in the animal world C. cloning can’t help those who want to clone their dead children D. cloning human embryos shows no respect for human life 53. Who is in favor of cloning human beings? A. Ian Wilmut.        B. Severino Antinori. C. The author.        D. The Chinese scientists. 54. What can be inferred from the last two paragraphs? A. If we interfere with nature, we will change the world to be what we want. B. It is impossible to clone babies for women who cannot have ones. C. Cloning human beings is illegal in many countries，so no scientists want to do so. D. Whether cloning human embryos is legal or not remains a matter of debate.