Read the article and select the best answer. Article: Elephants have impressed us for centuries. They are big, clever, and sociable. But what if someone told you that they may also hold the key to fighting cancer? People have been wondering why elephants do not develop cancer, even though they have life spans that are similar to humans, living for around 50 to 70 years. Now scientists believe they know why. A team at the University of Chicago, Us has found that elephants carry a large number of genes that stop tumors from developing. To be precise, they found 20 copies of an anti-tumor gene called TP 53 in elephants. Most other species, humans included, only carry one copy. According to the research, which was recently published on the online science network BioRxiv, the extra copies of the gene improved the animal's sensitivity to DNA damage. This lets the cells quickly kill themselves when damaged before they can form deadly tumors. "An increased risk of developing cancer has stood in the way of the evolution of large body sizes in many animals," study author Dr Vincent Lynch told The Guardian. If every living cell has the same chance of becoming cancerous, large creatures with long life spans like whales and elephants should have a greater risk of developing cancer than humans and mice do. But across species, the risk of cancer does not show a connection with body mass. _ was found by Oxford University scientist Richard Peto in the 1970s and later named "Peto's paradox". Evolutionary biologists believe it results from larger animals using protection that many smaller do not, In the elephant's case, the making of TP53 is nature's way of keeping this species alive. The study also found that when the same genes were brought to life in mice, they had the same cancer resistance as elephants. This means researchers could use the discovery to develop new treatments that can help stop cancers from spreading or even developing in the first place. "Nature has already figured out how to prevent cancer," said Joshua Schiffman, an oncologist at the School of Medicine,... Question: Why are elephants unlikely to develop cancer? Options: A: They have a large body size B: They carry many genes that keep tumors from developing C: Certain genes in their body kill existing tumors D: Their genes suffer no DNA damage
B

Read the article and select the best answer. Article: China's admiration of outstanding scholars has turned the well-preserved childhood home of TuYouyou,the Chinese pharmacologist who won this year's Nobel Prize in physiology or Medicine,into a popular tourist destination. Since it was announced on Monday that 84-year-old Tu had become the first Chinese citizen to win this international prize,her former home in the old town of Ningbo,Zhejiang province,has attracted visitors,especially parents and their children----even though it is not open to the public. The house,where Tu lived until she went to university in Beijing,covers an area of 2,200square meters and is priced at 150million yuan($23.6million).It is part of a complex of 37traditional buildings,including several city-and-district-level cultural relic preservation sites,that have been transformed into a high-end art,and commercial zone. "There are continually parents taking their children,from infants in strollers to college students,to take photos in front of Tu's former home.Security guards have been ordered to go on patrol around the clock,"said Mr.Zhao,a salesperson from Ningbo Real Estate Inc Co. Shanghai resident Xu Lingfei,who was on a trip to Ningbo,took her 9-year-old son to walk around the complex on Wednesday."Chinese people believe in exams and awards and have a strong preference for high performers.Taking children to visit the former dwelling places of celebrities is a way to inspire them to study harder,"Xu said. Something similar happened after Mo Yan won the Nobel Prize for literature in 2012.Tourists started visiting Mo's former home in rural Caomi,Shandong Province,in an endless stream starting the day after he won the prize.Some even pulled the radishes planted in front of the house.and carried away some bricks. Question: Tu Youyou's former house is now popular mainly because. . Options: A: Tu won the Nobel Prize B: it has some cultural relics C: it covers a large area D: it is a great art and commercial zone
A

Read the article and select the best answer. Article: My Best Enemy Once again, I was in a new school. So was a girl in my class named Lisa. That's where the similarities ended. I was tall and she was small. My thick black hair had been recently cut short into an untidy style. Her natural blonde hair flowed to her waist and looked great. I was 12 and one of the oldest in the class while she was 11 and the youngest. I was awkward and shy. She wasn't. I couldn't stand her, considering her my enemy. But she liked me and wanted to be friends. One day, she invited me over and I said yes--I was too shocked to answer any other way. My family had moved six times in six years, and I had never managed to develop any friendships. But this girl who wore the latest fashions wanted me to go home with her after school. She lived in a fun part of town that had two pizza places, an all-night bookstore, a movie theater and a park. As we walked from the school bus stop through her neighborhood, I tried to guess which house might be hers. Was it the white one with the perfect lawn or the three-story house with a front porch? I got very surprised when she led me into an old apartment building. She lived on the fourth floor in a two-room place with her mother,her stepfather, her two brothers and her sister. When we got into the room she shared with her sister, she took out a big case of Babies, which was my next surprise. I had never played with them. We sat on the floor,laughing as we made up crazy stories about the Babies. We found out that we both wanted to be writers when we were older and both had wild imaginations. We had a great day that afternoon. Lisa was loved by the whole neighborhood. The bookstore owners lent her fashion magazines; the movie theater gave her free tickets... Soon I was included in her magic world. We slept over at each other's houses and spent every free moment together. Lisa, my first real friend since childhood, helped me get through the rough year of early adolescence and taught me an amazing and very surprising thing about making friends: that your... Question: In the passage the writer described Lisa as a girl who was _ Options: A: awkward and shy B: rich and happy C: friendly and lovely D: quiet and lonely
C