Scientists may have found a way to reduce shortage of type O blood．Type O is the kind of blood that hospitals most often need．What the researchers are testing is an easier way to make type O blood out of other kinds of blood．
There are four main kinds of blood．Most people born with one of these four：Type A，Type B，Type AB or Type O．Type O can be safely given to anyone．So it is commonly used when a person is injured or sick and has to have blood．
Type O is the most common blood group．But the supplies of it available in hospitals and blood banks are usually limited．This is because of the high demand for it．Type O blood is used in emergencies when there is no time to identify the patient's blood type．
Giving A，B or AB to someone with a different blood type，including O，can cause a bad reaction by the person's defense system．Their immune system can reject the blood．This immune reaction can be deadly．
The differences among blood types are linked to whether or not red blood cells contain certain kinds of sugar molecules．These molecules are found on the surface of the cells．They are known as antigens（抗原）．These antigens are found with type A，B and AB blood but not with type O．
More than twenty-five years ago，scientists found that the antigens could be removed to create what they called universal-type cells．They could be removed with chemicals called enzymes（酶）．But large amounts of enzymes were required to make the change．
Doctor Henrik Clausen of the University of Copenhagen in Denmark led the study．The next step，he says，is to complete safety tests．The team is working with the American company ZymeQuest to test the new method．If it meets safety requirements（要求） and is not too costly，it could become a widely used life-saving tool to increase the supply of universal blood．
（1）How do scientists deal with the problem of lacking type O blood？ AA
A．Make type O blood out of other kinds of blood．
B．Make the most of the present type O blood．
C．Develop new ways of using type O blood．
D．Appeal to more people to donate type O blood．
（2）What make people have different kinds of blood？ AA
A．Sugar molecules in red blood cells．
B．People's different living conditions．
C．The variety of people's cells and genes．
D．People's various immune systems．
（3）What can we infer from the text？ DD
A．Antigens could easily be removed to create universal blood．
B．A Danish company wanted to involve itself in studying blood．
C．Type O blood can be safely given to anyone．
D．The new method is not safe enough to be put into use in hospitals now．
（4）What is the best title for the text？ BB
A．Four different kinds of blood．
B．A new way to make type O blood．
C．The latest research on blood type．
D．Find the proper type of blood．
【答案】A；A；D；B
【解答】
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發(fā)布：2024/4/20 14:35:0組卷：5引用：2難度：0.5
相似題
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1．For some people，the warmest memories from childhood come from being read a great story．（1）
It develops children's language skills and increases their ability to succeed in school and，later，work．
A new report by the American Academy of Pediatrics says reading aloud is so important that parents should start as soon as their children are born and continue to read aloud even after their children can read by themselves．They say parents should also point to and talk about pictures in books for infants（嬰幼兒）．（2）
The company Scholastic is fl major U．S．publisher of children's books．Every two years，Scholastic publishes a report on American reading attitudes and habits．The 2015 report says only 31 percent of children in the U．S．read a book for fun almost every day．
（3）One is simply to have books in the home．Elizabeth Lyttleton，the mother of three，is lucky．Her mother once wrote and illustrated children's books，so the family always have plenty to read．She says all her children learn from books-but in different ways．（4）Researchers from the Scholastic company found that 80%of children surveyed-of all ages-say they love being read to．And children ages 6 to 11 whose parents do not read to them anymore say they miss it．
（5）Of all the six to 17-year-olds in the Scholastic study，more than 90%said their favorite books are the ones they chose for themselves．
A．The Scholastic report also suggests permitting children to choose their own books．
B．Scholastic also identifies some ways to develop a love of reading in a child．
C．A book does not have to be serious to be good for kids．
D．For young children，parents should ask questions about the book．
E．Do children still read for fun？
F．Another way to develop a reading habit in children is to read to them．
G．But reading to children does more than create warm memories．發(fā)布：2025/1/1 13:30:1組卷：14引用：7難度：0.7 -
2．Chinese students always complain that they're under great pressure and don't get enough sleep.But they may be surprised to learn that they're much luckier than their peers（同齡人）in South Korea and Japan，according to a recently published report，conducted by Shanghai Academy of Social Sciences on the physical and mental health of senior high school students in the three Asian countries.
According to the study among nearly 6，000 high school students in the three countries，Chinese students are the tallest but poorest in physical fitness.Chinese students are on average 168.17cm，compared with 167.61cm for South Korean students and 164.70cm for Japanese students.Chinese students asked for sick leave more than students in other countries.About 72 percent of Korean students never asked for sick and injury leave during high school，compared to 53 percent for Japanese students and 45 percent for Chinese students.Moreover，Chinese students drink alcohol and smoke earlier than Korean and Japanese students.Around 70 percent of Chinese students have drunk alcohol，compared to 50 percent for Korean and Japanese students.
According to the survey，Japanese and South Korean students suffer more pressure than their Chinese peers.Statistics show 16 percent of students in China said they experienced mental pressure often over the past year，while the numbers in Japan and South Korea were 33 percent and 47 percent respectively.Their worries come from "study"，"future after graduation"， "friendships" and "relationship with their parents".To go with stress，57.9 percent of Korean students sleep the least，less than six hours a day，compared with 46.6 percent of Japanese students and 30 percent of Chinese students.
More Chinese students were satisfied with their physical appearance，double that of students in the survey from Japan and South Korea.The report said that over half of students in South Korea had tried to lose weight in the past year，while in China the figure was only 22 percent.In measures of self-worth，such as "I think I am valuable" and "I think I am successful"，"I can complete many things"， "I won't give up to failure，" Chinese students showed greater self-confidence than students in Japan and South Korea.
（1）What's the main idea of the second paragraph？
A．Chinese students ask for sick leave most often.
B．Chinese students drink most alcohol and smoke earliest.
C．Japanese students ask for least sick leave.
D．Chinese teenagers are tallest，but most unhealthy.
（2）It can be inferred from the passage that.
A．Chinese students are confident in themselves and luckier
B．Chinese students are luckiest，yet most unsuccessful
C．Japanese students are most stressed
D．South Korean students sleep the least
（3）What does the underlined word "that" refer to？
A．the height
B．the number
C．the weight
D．the appearance
（4）The worries that causes students to be stressed come from the following factors EXCEPT.
A．study and career
B．friendships
C．physical appearance
D．family relationship發(fā)布：2025/1/1 16:0:1組卷：0引用：3難度：0.5 -
3．Paying ﹩25，000 to get your pet cloned might sound attractive，if you have the money and can't imagine life without your pet.
There are two companies now that can clone your pet：ViaGen and Sooam Biotech.Lab techs there will clone your pet using a process called somatic cell nuclear transfer （體細(xì)胞核移植），the same method used to clone Dolly the sheep in 1996.This involves removing the nucleus from a female's developing egg cell and replacing it with the nucleus from a cell from the animal you want to clone.The new cell is then stimulated （刺激） with an electric shock to make it divide and then implanted into a host organism （有機(jī)體）.
The decision to clone your pet has to take place while they're still alive.You need to sign up with the company and take your pet to the vet so they can harvest some cells.Then，for between ﹩1-2000，the company will store the cells.Even if you decide to stop，there's no refund for the storage.If you decide to have your pet cloned，you'll pay a much larger deposit to perform the cell transfer and implant the cells into a host animal.
What's most important to consumers is the product.Your clone is a twin of your former pet，but it won't necessarily look or act like the original.They may have different colors and you don't get your money back.Even the companies admitted in New York Times "You can clone the look of a dog，but you can't clone the soul."
（1）Why did the author mention Dolly the sheep？
A．To ensure the safety of cloning.
B．To show that it is easy to clone sheep.
C．To prove the technology has a long history.
D．To tell readers the method used to clone their pets.
（2）What can we know about cloning a pet？
A．Your pet can be brought back to life.
B．The charge of pet cloning is ﹩1-2000.
C．Your new pet will have a parent when cloned.
D．The company will refund you if you give up halfway.
（3）What do the companies' words in the last paragraph mean？
A．Cloning is a moral issue.
B．The future of cloning is unclear.
C．The technology of cloning is not perfect.
D．Yon won't get the exact copy of the former one.
（4）Where is the text most likely from？
A．A travel guide.
B．A newspaper.
C．A science fiction.
D．A textbook.發(fā)布：2025/1/1 16:0:1組卷：21引用：4難度：0.5