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题型:阅读理解-阅读单选 难度:0.65 引用次数:72 题号:10446776

Why elephants rarely get cancer is a mystery that has confused scientists for decades. A study led by researchers at Huntsman Cancer Institute (HCI), at the University of Utah and Arizona State University may have found the answer.   

According to the results, elephants have 38 additional modified copies of a gene that encodes p53, a definite tumor suppressor, as compared to humans, who have only two. Further, elephants may have a more powerful mechanism for killing damaged cells that are at risk for becoming cancerous. In isolated elephant cells, this activity is doubled compared to healthy human cells, and five times that of cells from patients with Li-Fraumeni Syndrome, who have only one working copy of p53 and more than a 90 percent lifetime cancer risk in children and adults. The results suggest extra p53 could explain elephants’ increased resistance to cancer.

“Nature has already figured out how to prevent cancer. It’s up to us to learn how different animals overcome the problem so we can adapt those strategies to prevent cancer in people,” says co-senior author Joshua Schiffman, M.D., pediatric oncologist (儿科肿瘤医生) at Huntsman Cancer Institute, University of Utah School of Medicine.

But Prof Mel Greaves, from the Institute of Cancer Research in London, says we should focus on why humans have such high levels of cancer. He pointed to the rise of unhealthy, cancer-causing behaviors, such as obesity and sunbathing. “You’ve never seen an elephant smoke!” he added.

According to Schiffman, elephants have long been considered a walking problem. Because they have 100 times as many cells as people, they should be 100 times more likely to have a cell slip into a cancerous state and cause the disease over their long life span of 50 to 70 years. And yet analysis of a large database of elephant deaths estimates a cancer death rate of less than 5 percent compared to 11 to 25 percent in people.

1. Why are elephants less likely to get cancer than humans?
A.Elephants are bigger than humans.
B.Elephants have more p53 genes and mechanism killing damaged cells.
C.Elephants are not as clever as humans in walking.
D.Elephants eat more than humans.
2. Which of the following can be the equivalent of the underlined word “suppressor”?
A.multiplierB.complexC.restrainerD.coordinator
3. What’s Prof Mel Greaves’ attitude towards the discovery?
A.Doubtful.B.Neutral.C.Critical.D.Favorable.
4. What can we infer from the last paragraph?
A.Elephants have longer life than people.
B.There is no chance that elephants die from cancer.
C.The rate of elephants dying from cancer is increasing.
D.It was thought theoretically that elephants could get cancer more easily.

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文章大意:本文是一篇新闻报道。一位来自美国缅因州波特兰市的渔民在缅因州海岸捕获了一只非常罕见的蓝龙虾,但他选择将其放回大海。

【推荐1】A fisherman from Portland, Maine, the US, caught a very rare bright blue lobster (龙虾) off the coast of Maine but chose to set it free back into the ocean. The photo of the blue lobster was shared by tech enterpriser Lars-Johan Larsson. “This blue lobster was caught off the coast of Portland yesterday and returned to the water to continue to grow. Blue lobsters are one in two million,” he wrote.

While the shells of lobsters are generally red or brown in color, the blue shell is a result of gene mutation (基因突变), which causes the lobster to produce more of a particular protein than other lobsters, leading to the rare blue color, as reported by the Toronto Sun.

Yellow, orange and crystal-colored lobsters are considered even rarer than bright blue ones. According to the Lobster Institute, yellow lobsters account for about one in 30 million of the total population. Two fishermen in Dorset caught a crystal-colored lobster in 2011.

“Whatever the odds of catching different-colored lobsters, there’s no denying that bright blue ones are truly beautiful creatures,” said Rob Bayer, executive director of the University of Maine Lobster Institute. “They might not be the most unusual, but they’re undoubtedly the best to look at.”

It’s become something of a trend for restaurants to spare blue lobsters. Austin Hopley, a chef at “The Hare” in Rochdale, the UK, made the news for sparing a bright blue lobster. He gave it to Sea Life in Manchester, as reported by the BBC.

“Now it’s there for people to enjoy,” said Hopley. “I felt responsible. Something so rare didn’t require a place on the menu. Every species deserves a fair chance at survival.”

Expert Brendan Malone from Sea Life said, “It is certainly an extraordinary find and worth saving to try to educate the public about these amazing creatures in the ecosystem.”

1. What is the root cause for the color of blue lobsters?
A.Gene variation.B.Adaptation failure.
C.A specific protein.D.A mix of red and brown.
2. What does Rob Bayer think of blue lobsters?
A.They are the rarest.B.They are easy to catch.
C.They are delicious to eat.D.They are most beautiful.
3. Why was Hopley unwilling to cook the blue lobster?
A.It wouldn’t make a good dish.
B.He wanted to follow the trend.
C.He took on responsibility to save it.
D.It would bring him fame and profits.
4. Which can serve as the best title?
A.Blue Lobsters Rebound Suddenly
B.Chefs Take Action to Protect Lobsters
C.Gene Mutation Has an Effect on Lobsters
D.Man Catches a “One in Two Million” Blue Lobster
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【推荐2】Pandas are not only a national treasure, but are loved around the world.

Recently, a giant panda cub born in August at the Smithsonian’s National Zoo, US, was given the name Xiao Qi Ji, which is translated into English as “little miracle”. The choice was the result of a five-day online vote that drew nearly 135,000 voters in the US. Interestingly, National Public Radio said that in a nod to Chinese tradition, the name was not chosen until 100 days after the birth.

This cub’s birth proved to be quite inspiring - and at a time when inspiration was truly needed.

“Xiao Qi Ji’s birth is a true miracle that has been so uplifting to all of us during the pandemic (疫情),” Chinese Ambassador to the US Cui Tiankai said in a video congratulatory message. “ We are connected again in the growth of our little ambassador, and in our shared joy and friendship.”

The furry black-and-white animals have played an important role in the country’s diplomacy, known as “ panda diplomacy (外交)”.

According to the Japanese Royal Annual, the practice dates back to the Tang Dynasty, when Empress Wu Zetian sent a pair of pandas to the Japanese emperor.

China revived panda diplomacy in the 1950s when China sent two pandas to the Moscow Zoo. By 1982, China had given 23 pandas to nine different countries. However, most of them have died. China stopped giving away pandas in the early 1980s. Instead, the animals are loaned to other countries. In general, they are to be returned to China after 10 years.

But why do these cute “diplomats” find it hard to survive in other countries? According to Xinhua, their dietary habit is one significant reason. Their nutrition mostly comes from bamboo shoots. Adult giant pandas consume about 40 kilograms of bamboo daily. Pandas can also be quite picky. They refuse to eat bamboo shoots after they have blossomed.

It takes 10 years for a new crop of bamboo to mature, and many countries do not have an environment suitable for bamboo growth. This means that food has to be imported In August, Calgary Zoo in Canada announced that due to pandemic-related changes in its import laws and quarantine methods, they couldn’t provide enough fresh bamboo for pandas. This meant that they had to send two giant pandas back to China.

But countries are still trying their best to facilitate this special type of diplomacy. “We don’t own the pandas, but the whole world wants to help save the panda, and we do that through our knowledge exchange.” Steven Monfort, director of the Smithsonian’s National Zoo, told China Daily.

1. The expression “in a nod to” in Para. 2 is closest in meaning to________.
A.in praise forB.in response toC.in favor ofD.in order to observe
2. Why China decided that pandas are only loaned to other countries?
A.Because the pandas’ dietary habit was significantly changed abroad.
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C.Because most of pandas could not be adapted to the climate abroad.
D.Because most of the pandas sent to other countries couldn’t survive.
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A.It was the first time that China had sent a panda to Japan.
B.The practice “panda diplomacy” dales from the Tang Dynasty.
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D.Two giant pandas had to be returned because they were sick in Canada.
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A.Favorable.B.Uncaring.C.Disapproving.D.Doubtful.
5. What is the purpose of the passage?
A.To tell us how to feed pandas properly.B.To call on people to love pandas in the world.
C.To introduce the furry black and white ambassador.D.To explain why “panda diplomacy” is stopped.
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【推荐3】阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项。
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