Canpeoplechangetheirskincolorw

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更新 2022-09-03
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Can people change their skin color without suffering like pop king Michael Jackson? Perhaps yes.Scientists have found the gene that determines skin color.
The gene comes in two versions, one of which is found in 99 per cent of Europeans.The other is found in 93 t0 100 per cent of Africans, researchers at Pennsylvania State University report in the latest issue of Science.
Scientists have changed the color of a dark - striped zebrafish(斑马鱼) to uniform gold by inserting a version of the pigment(色素) gene into a young fish.As with humans, zebrafish skin color is deter-mined by pigment cells，which contain melanin(黑色素).The number, size and darkness of melanin perpigment cell determine skin color.
It appears that, like the golden zebrafish, light - skinned Europeans also have a mutation (变异) in the gene for melanin production.This results in less pigrnented skin.
However, Keith Cheng, leader of the research team, points out that the mutation is different in hu-man ancl zebrafish genes.
Humans acquired dark skin in Africa about l.5 million years ago to protect bodies from ultra - violetrays of the sun. which can cause skin cancer.
But when modem humans leave Africa to live in northem 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 color, said Cheng.
The new discovery could lead to medical treatments for skin cancer.lt also could lead to research in-to ways to change skin color without damaging it like chemical treatment did on Michael Jackson.
Scientists have done an experiment on a dark -striped zebrafish in order to

A．fincl the different genes o humans'

B．prove the humans' skin color is determined by the pigment gene

C．find out the reason why the Africans' skin color is dark

D．fincl out the ways of changing people's skin color

lt can be inferred from the passage that .

A．nowadays people who want to change their skin color have to suffer 8 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

The passage mainly tells us that .

A．scientists have found out that people's skin color is determined by the gene

B．the new discovery could lead to research into ways to change skin color safely

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

D．people can not change their skin color without any pain

The reason why Europeans are light - skinned is probably that .

A．they are bom light - skinned people

B．light - skinned Europeans have mutation in the gene for melanin production

C．they have fewer activities outside

D．they pay much attention to protecting their skin

The writer's attitude towarcls the discovery is .

A．neutral

B．negative

C．indifferent

D．positive

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One Sunday, my family had gathered at my parents’ house to feast upon Mom’s wonderful cooking．During the normal dinner chatter, I noticed that my father was slurring （说话含混） his words．No one mentioned this during dinner, but I felt compelled to discuss it with my mother afterward．
We decided that there was something seriously wrong and that Dad needed to see the doctor．
Mom phoned me two days later．“The doctor found a brain tumor （肿瘤）．It’s too large at this point to operate．Maybe they can do something then, but the odds are long．”
Even with the treatment, my father’s condition worsened, and the doctor finally informed us that this condition was terminal．During one of his stays in the hospital, we brought our baby daughter Chelsey with us when we visited him．By this time he had great difficulty speaking．I finally figured out that he wanted Chelsey to sit on his stomach so he could make faces at her．
Watching the two of them together, I realized I was living an experience that would stay with me forever．Though grateful for the times they could share, I couldn’t shake the feeling of a clock ticking in the background．
On the visit to my parents’ home during what we all know was my father’s last days, my mother took Chelsey from my arms and announced, “Your father would like to see you alone for a minute．”
I entered the bedroom where my father lay on a rented hospital bed．He appeared even weaker than the day before．
“How are you feeling, Dad?” I asked．“Can I do anything for you?”
He tried to speak, but he couldn’t make out a word．
“I’m sorry, but I can’t understand you,” I said．
With great difficulty he said, “I love you．”
We don’t learn courage from heroes on the evening news．We learn true courage from watching ordinary people rise above hopeless situations．In many ways my father was a strict, uncommunicative man．He found it difficult to show emotion．The bravest thing I ever saw him do was overcome that barrier to open his heart to his son and family at the end of his life．
What does the underlined sentence “the odds are long” mean?

A．It takes a long time for Father to recover．

B．There’s little possibility for Father to recover．

C．Father needs love and care from his family．

D．They need a proper time to operate on Father．

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Unlike chemists and physicists, who usually do their experiments using machines, biologists and medical researchers have to use living things like rats. But there are three Nobel prize-winning scientists who actually chose to experiment on themselves – all in the name of science, reported The Telegraph.
1. Werner Forssmann (Nobel prize winner in 1956)
Forssmann was a German scientist. He studied how to put a pipe inside the heart to measure the pressure inside and decide whether a patient needs surgery.
Experiments had been done on horses before, so he wanted to try with human patients. But it was not permitted because the experiment was considered too dangerous.
Not giving up, Forssmann decided to experiment on himself. He anaesthetized (麻醉) his own arm and made a cut, putting the pipe 30 centimeters into his vein. He then climbed two floors to the X-ray room before pushing the pipe all the way into his heart.
2. Barry Marshall (Nobel prize winner in 2005)
Most doctors in the mid-20th century believed that gastritis was down to stress, spicy food or an unusually large amount of stomach acid. But in 1979 an Australian scientist named Robin Warren found that the disease might be related to a bacteria called Helicobacter pylori.
So he teamed up with his colleague, Barry Marshall, to continue the study. When their request to experiment on patients was denied, Marshall bravely drank some of the bacteria. Five days later, he lost his appetite and soon was vomiting each morning – he indeed had gastritis.
3. Ralph Steinman (Nobel prize winner in 2011)
This Canadian scientist discovered a new type of immune system cell called the dendritic cell. He believed that it had the ability to fight against cancer.
Steinman knew he couldn’t yet use his method to treat patients. So in 2007, when doctors told him that he had cancer and that it was unlikely for him to live longer than a year, he saw an opportunity.
With the help of his colleagues, he gave himself three different vaccines based on his research and a total of eight experimental therapies（疗法）. Even though Steinman eventually died from his cancer, he lived four and a half years, much longer than doctors had said he would.
The underlined word “gastritis” in Paragraph 5 probably means ______.

A．a kind of bacteria	B．a kind of stomach disease
C．a new type of therapy	D．a large amount of stomach acid

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Occasionally, my father came back drunk. Late at night, he beat on the door, pleading to my mother to open it .He was on his way home from drinking, gambling, or some combination thereof, misspending money that we could have used and wasting time that we desperately needed.
It was the late-1970s. My parents were separated. My mother was now raising a group of boys on her own. My father spouted off about what he planned to do for us, buy for us.In fact, he had no intention of doing anything. As a father who was supposed to love us, in fact, he lacked the understanding of what it truly meant to love a child—or to hurt one. To him, this was a harmless game that kept us excited and begging. In fact, it was a cruel, corrosive lie. I lost faith in his words and in him. I wanted to stop caring, but I couldn’t.
Maybe it was his own complicated relationship to his father and his father’s family that caused him cold. Maybe it was the pain and guilt associated with a life of misfortune. Who knows. Whatever it was, it stole him from us, and particularly from me.
While my brothers talked about breaking and fixing things, I spent many of my evenings reading and wondering. My favorite books were a set of encyclopedias(百科全书) given by my uncle. They allowed me to explore the world beyond my world, to travel without leaving, to dream dreams greater than my life would otherwise have supported. But losing myself in my own mind also meant that I was completely lost to my father. Not understanding me, he simply ignored me—not just emotionally, but physically as well. Never once did he hug me, never once a pat on the back or a hand on the shoulder or a tousling of the hair.
My best memories of him were from his episodic attempts at engagement with us. During the longest of these episodes（插曲）, once every month or two, he would come pick us up and drive us down the interstate to Trucker’s Paradise, a seedy, smoke-filled, truck stop with gas pumps, a convenience store, a small dining area and a game room through a door in the back. My dad gave each of us a handful of quarters, and we played until they were gone. He sat up front in the dining area, drinking coffee and being particular about the restaurant’s measly offerings.
I loved these days. To me, Trucker’s Paradise was paradise. The quarters and the games were fun but easily forgotten. It was the presence of my father that was most treasured. But, of course, these trips were short-lived.
It wasn’t until I was much older that I would find something that I would be able to cling to as evidence of my father’s love.
When the Commodore 64 personal computer debuted, I convinced myself that I had to have it even though its price was out of my mother’s range. So I decided to earn the money myself. I mowed every yard I could find that summer for a few dollars each, yet it still wasn’t enough. So my dad agreed to help me raise the rest of the money by driving me to one of the watermelon farms south of town, loading up his truck with wholesale melons and driving me around to sell them. He came for me before daybreak. We made small talk, but it didn’t matter. The fact that he was talking to me was all that mattered. I was a teenager by then, but this was the first time that I had ever spent time alone with him. He laughed and repeatedly introduced me as “my boy,” a phrase he relayed with a sense of pride. It was one of the best days of my life.
Although he had never told me that he loved me, I would cling to that day as the greatest evidence of that fact. He had never intended me any wrong. He just didn’t know how to love me right. He wasn’t a mean man. So I took these random episodes and clung to them like a thing most precious, storing them in my mind for the long stretches of coldness when a warm memory would prove most useful.
It just goes to show that no matter how friendless the father, no matter how deep the damage, no matter how shattered the bond, there is still time, still space, still a need for even the smallest bit of evidence of a father’s love.
“My boy.”
The underlined phrase “cling to” can be replaced by __________.

A．catch hold of	B．depend on
C．stick to	D．keep

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Recently, the TV show “Where are we going, Dad?” produced by Hunan SatelliteTelevision is a big hit across nation. Many famous stars brought their children to a strange village alone, and they had to spend 72 hours with their children there. The program fully showed us a modern version of the “how to be a good father”. As the young parents today are too busy to take care of their children, this new form of “Lost on the way” played by nanny Daddy and cute kids triggered（触发）a lot of people’s emotional resonance（共鸣）. Both the kids and their parents will find that their hearts are being drawn closer. But this kind of feeling has just proved that there is a big spiritual barrier between the modern parents and children.
The TV shows like “Children are hard to support!”, “Where are we going, Dad?”, “hot mom” and “cute kids” are becoming more and more popular. All of these show the new parents’ confusion in children’s education and the appeal for the balance between career and family.
In the real life, on the one hand the young parents feel helpless because they are too busy to accompany their children under the pressures of work and life; on the other hand they continue to do so. The data collected by HNTV shows that nearly two-thirds of their audience are female, among whom 36% are aged from 25 to 34.We can imagine such a scene that one evening a young mother is watching the show with her young children, while her husband is still at work or trapped in socializing, or maybe is just playing computer games in the bedroom. The story of a child without the company of father is still going on. In fact, it is sometimes the same to mothers. In a modern family, it is often the old who take the responsibility of raising a child. The participation of mother in the children’s education is also very low.
It is just this kind of confusion where the parents have gone in the modern family education, and where the parents will guide their children to go that “Where are we going, Dad?” shows us. If a child wants to grow up healthily and safely into a modern citizen with independent personality and free spirit, it is very important for him or her to follow the parents who serve as their first teacher. Maybe this is the real reason why such kind of TV programs could get hot. The truth is that children will go where their parents go; and society will go where the children go.
What does the underlined word “participation” probably mean?

A．taking responsibility	B．understanding
C．taking part	D．keeping company

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Searching for airfares（飞机票价） often seems like a game that passengers are bound to lose．
Prices change from day to day, even minute to minute． Looking through multiple websites for the best deal can be a big challenge． Even when you do book, there’s no guarantee that you are going to get the best price．
"You just don’t know when to pull the trigger． It’s not like buying anything else I can think of,” said George Hobica, founder of Airfarewatchdog．com．
Harriet Levy paid $179 for a recent round-trip flight on American Airlines between New York and Fort Lauderdale, Florida． Sitting just one row behind her, Shirley Harrison paid $215． A few rows back, Ellis and Dianne Traub paid $317 each．There were at least 12 fares on the flight, ranging from $169 to $360．
There’s no reason for it, Harrison said．
Fares can change significantly in just a few hours． One Delta flight from New York to Los Angeles jumped from $755 to $1,143 from a Friday to Saturday in late April, then fell to $718 0n Sunday．
The flight was one of a dozen the Associated Press followed over three months for a vacation between July 16 and 22． The number one finding: avoid booking tickets on weekends． It’s the most expensive time to buy．
There’s no way to guarantee the best fare． But before booking, travelers should pay attention to this additional advice:
Book on Tuesday, Wednesday and Thursday． That’s when airlines most often offer sales．
Buy in advance, but not too early． The best time is four to six weeks before traveling． In general, prices for any given flight are highest eight to ten weeks and two to three weeks in advance．
Make use of social media． Airlines are giving more benefits like exclusive（独有的） sales to travelers who interact with them on Twitter and Facebook． Those specials are often gone within hours．
The so-called discount airlines - JetBlue, Air-Tran, Southwest and Frontier-adjust their fares less frequently than other airlines, so you can feel more confident that the price will stay the same． But their prices aren’t always the lowest．Researching multiple airlines’ fares is the only way to get a good deal．
The underlined phrase "pull the trigger" in Paragraph 3 probably means ________.

A．start searching	B．get the highest price
C．make a purchase	D．get on board the plane

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