52. It can be inferred from the passage that ________.

　 A. nowadays people who want to change their skin colour have to suffer a lot from the damage caused by the chemical　 treatment

　 B. Europeans and Africans have the same gene

　 C. the new discovery could help to find medical treatments for skin cancer

　 D. there are two kinds of genes

51. The passage mainly tells us that ________.

　 A. people can not change their skin colour without any pain

　 B. the new discovery could lead to search into ways to change skin colour safely

　 C. pop king Michael Jackson often changed his skin colour as he liked

　 D. scientists have found out that people’s skin colour is determined by the gene

50. What is the advantage of the Jerry Springer show?

　 A. The show exposes the dark sides of society.

　 B. The show pours poisonous waste into society.

　 C. Jerry sums up the whole idea of the show.

　 D. Jerry talks abou the improvement of society.

C

Can people change their skin colour without suffering like pop king Michael Jackson? Perhaps yes. Scientists have found the gene that determines skin colour.

The gene comes in two versions, one of which is found in 99 per cent of Europeans. The other is found in 93 to 100 per cent of Africans, researchers at Pennsylvania State University report in the latest issue of Science.

Scientists have changed the colour of a dark-striped zebrafish to uniform gold by inserting a version of the pigment(色素) gene into a young fish. As with humans, zebrafish skin colour is determined by pigment cells, which contain melanosomes(黑色素). The number, size and darkness of melanosomes per pigment cell determines skin colour.

It appears that, like the golden zebrafish, light-skinned Europeans also have a mutation(变异) in the gene for melanosome production. This results in less pigmented skin.

However, Keith Cheng, leader of the research team, points out that the mutation is different in human and zebrafish genes.

Humans acquired dark skin in Africa about 1.5 million years ago to protect bodies from ultra-violet rays of the sun(太阳光紫外线), which can cause skin cancer.

But when modern humans leave Africa to live in northern latitudes, they need more sunlight on their skin to produce vitamin D. So the related gene changes, according to Cheng.

Asians have the same version of the gene as Africans, so they probably acquired their light skin through the action of some other gene that affects skin colour, said Cheng.

The new discovery could lead to medical treatments for skin cancer. It also could lead to research into ways to change skin colour without damaging it like chemical treatment did on Michael Jackson.

46. Compared with other TV talk shows, both the Jerry Springer and the Oprah Winfrey shows are ______.

A. more interesting 　　　　　 B. unusually poplar 　　　 C. more detailed 　　　　　 D. more formal 47. Though the social problems Jerry Springer talks about appear unpleasant, people who watch the shows ______. 　 A. show disbelief in them　　　　　　　　　　　　　　　　　　　 B. are ready to face up to them 　 C. remain cold to them　　　　　　　　　　　　　　　　　　　　 D. are willing to get away from them 48. Which of the following is likely to be a topic of the Oprah Winfrey show? 　 A. A new type of robot.　　　　　　　　　　　　　　　　　　　　 B. National hatred. 　 C. Family income planning.　　　　　　　　　　　　　　　　　 D. Street accident. 49. We can learn from the passage that the two talk shows ____. 　 A. have become the only ones of its kind　　　　　　　　 B. exploit the weaknesses in human nature

C. appear at different times of the day　　　　　　　　　　 D. attract different people

45. What’s the main idea of the text?

　 A. A student’s silly question.　　　　　　　　　　　　　　　　　 B. A good teacher who likes students.

　C. A confused student.　　　　　　　　　　　　　　　　　　　　 D. The reason why I teach.

B

Among various programs, TV talk shows have covered every inch of space on daytime television. And anyone who watches them regularly knows that each one is different in style. But no two shows are more opposite in content, while at the same time standing out above the rest, than the Jerry Springer and Oprah Winfrey shows.

Jerry Springer could easily be considered the king of "rubbish talk". The topics on his show are as surprising as can be. For example, the show takes the ever-common talk show titles of love, sex, cheating, and hate, to a different level. Clearly, the Jerry Springer show is about the dark side of society, yet people are willing to eat up the troubles of other people's lives.

Like Jerry Springer, Oprah Winfrey takes the TV talk show to its top. But Oprah goes in the opposite direction. The show is mainly about the improvement of society and different quality of life. Contents are from teaching your children lessons, managing your work week, to getting to know your neighbors.

Compared to Oprah, the Jerry Springer show looks like poisonous waste being poured into society. Jerry ends every show with a "final word". He makes a small speech about the entire idea of the show. Hopefully, this is the part where most people will learn something very valuable.

Clean as it is, the Oprah show is not for everyone. The show's main audience are middle-class Americans. Most of the people have the time, money and ability to deal with life's tough problems. Jerry Springer, on the other hand, has more of a connection with the young adults of society. These are 18-to 21year-olds whose main troubles in life include love, relationship, sex, money and drug. They are the ones who see some value and lessons to be learned through the show's exploitation.

44. We can infer from the text that _________.

　 A. the writer was also a good teacher in school

　 B. the writer often plays with her students beside a pond

　 C. the writer devotes herself to teaching and her students

　 D. the writer often accompanies the students on their way home

43. According to the text, which of the following is NOT true?

　 A. The writer’s mother has the greatest influence on her.

　 B. The writer’s answer made the student confused.

　 C. In the writer’s opinion, some people in the world are unfit to teach.

　 D. The writer annoyed the student who asked the question.

42. What do you think of the writer?

　 A. Stupid. 　　　　　　　　　　　 B. Honest.　　　　　　　　　　 C. Conservative.　　　　　　　　　 D. Polite.

41. Why did the student continue to ask the question about the writer’s being a teacher?

　 A. Because he thought her answer was unbelievable.

　 B. Because the writer was insincere.

　 C. Because the student was naughty.

　 D. Because the answer was difficult to understand.