Chinese scientists have found a new way to use cells found in human urine （尿液）that could aid in the treatment of a range of nerve disorders.That is a new technique for reprogramming cells in human urine into nerve progenitor cells that can grow into multi-functional nerve and brain cells.
The technique is expected to be used in the study and treatment of nerve disorders such as Parkinson's disease, Alzheimer's disease and other nerve disorders.
Pei Duanqing, a professor at Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, said his research team has combined an episomal system to deliver reprogramming factors with a chemically defined culture medium to reprogram kidney epithelial(肾表皮) cells in urine into NPCs.
These NPCs, normally only found in the human brain, were later proven to be transgene-free and self-renewing, he said.
"These nerve and brain cells can survive for up to one month when transplanted into the brain of a newborn rat," said Pei. "My team is working hard to understand why our experimental condition allowed the urine cells to become NPCs, because we want to improve the technique and make it more efficient".
Scientists have long searched to treat and study neural disorders by obtaining and transplanting neural stem cells. However, the previous method of getting and using cells from either fetal (胎儿)or adult human tissue remains challenging due to ethical concerns and immune system rejections, he said.
Pei hopes the discovery will be used to generate NPCs from patients with nerve disorders such as Parkinson's disease. "These NPCs from patients may help us discover new drugs for these diseases."
"It is a remarkable advance in the stem cell field. The results and methods obtained from this study will be of great value and significance to the field, " said Fred Gage,a professor with the Salk Institute for Biological Studies.What is the passage mainly about?
| A．NPCs are beneficial in treating human diseases. |
| B．Chinese scientists succeeded in making NPCs from human urine. |
| C．Chinese scientists have found cures for all diseases. |
| D．A new technique was used to study the use of human urine |
Pei and his team try their best to work hard in order to .
| A．make more contributions to medical study |
| B．discover another new technique |
| C．make the technique more perfect |
| D．treat more patients suffering from bad diseases |
What is the challenge of making NPCs in the previous method?
| A．The ethical concerns and immune system refusal |
| B．The difficulties in getting cells from human. |
| C．The under-developed techniques in medical science. |
| D．The lack of financial support from the government |
From the last paragraph we can infer .
| A．the new technique will be developed in science |
| B．the result and methods will be applied to treating cancers |
| C．the study will give a major push to the stem cell field |
| D．the new technique will bring great profits |
Until the 1980s, the American homeless population is mainly made up of older males. Today, homelessness strikes much younger part of society. In fact, a 25-city survey by the U. S. Conference of Mayors in 1987 found that families with children make up the fastest growing part of the homeless population. Many homeless children gather in inner cities; this transient(变化无常的) and frequently frightened student population creates additional problems — both legal and educational — for already overburdened urban school administrators and teachers.
Estimates of the number of homeless Americans range from 350,000 to three million. Likewise, estimates of the number of homeless school children vary radically. A U.S. Department of Education report, based on state estimates, states that there are 220,000 homeless school-age children, about a third of whom do not attend school on a regular basis. But the National Coalition for the Homeless estimates that there are at least two times as many homeless children, and that less than half of them attend school regularly.
One part of the homeless population that is particularly difficult to count consists of the “throwaway” youths who have been cast of their homes. The Elementary School Center in New York City estimates that there are 1.5 million of them, many of whom are not treated as children because they do not stay in family shelters and tend to live by themselves on the streets.
Federal law, the Stewart B. McKinney Homeless Assistance Act of 1987, includes a section that addresses the educational needs of homeless children. The educational provisions（规定） of the McKinney Act are based on the belief that all homeless children have the right to a free, appropriate education.It is implied in the first paragraph that ____.
| A．the writer himself is homeless, even in his eighties |
| B．many older homeless residents are going on strike in 25 cities |
| C．there is a serious shortage of academic facilities |
| D．homeless children are denied the opportunity of receiving free education |
The National Coalition for the homeless believes that the number of homeless children is _____.
| A．350,000 | B．1,500,000 | C．440,000 | D．110,000 |
One part of the homeless population is difficult to estimate. The reason might well be ____.
| A．the homeless children are too young to be treated as children |
| B．the homeless population is growing rapidly |
| C．the homeless children usually stay outside school |
| D．some homeless children are deserted by their families |
The McKinney Act is mentioned in this passage in order to show that ___.
| A．the educational problems of homeless children are being recognized |
| B．the estimates on homeless children are hard to determine |
| C．the address of grade-school children should be located |
| D．all homeless people should have free education |
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E-mail: harcourt@learning.comThis advertisement aims at calling on people to ________.
| A．attend full-time universities |
| B．work part time to further their education |
| C．improve their education at home to get better jobs |
| D．earn their degrees in different ways that suit them |
Which of the following is NOT clearly mentioned in this advertisement?
| A．The way how you will get your degree. |
| B．Tuition price. |
| C．The hot fields you will be preparing yourself for. |
| D．The length of time it will take you to get a degree. |
What does the writer of this ad intend to say by naming General Electric, IBM, Ford, etc.?
| A．To show that their training is widely used in the country. |
| B．To show that the training program is fully supported by famous companies in the U. S. |
| C．To prove the value of their training in every area. |
| D．To show the importance of getting recognized by the most famous companies. |
It seems to the writer that the greatest attraction for people to take their training is______.
| A．its convenience |
| B．the degree’s nation-wide recognition |
| C．the economic benefit it will bring about |
| D．the hot fields the training will help people to enter |
Shopping for clothes is not the same experience for a man as it is for a woman. A man goes shopping because he needs something. His purpose is settled and decided in advance. He knows what he wants, and his objective is to find it and buy it; the price is a secondary consideration. All men simply walk into a shop and ask the assistant for what they want. If the shop has it in stock(有现货的), the salesman promptly produces it, and the business of trying it on follows at once. All being well, the deal can be and often is completed in less than five minutes, with hardly any chat and to everyone's satisfaction.
For a man, slight problems may begin when the shop does not have what he wants, or does not have exactly what he wants. In that case the salesman, as the name implies, tries to sell the customer something else, he offers the nearest to the article required. No good salesman brings out such a substitute impolitely; he does so with skill: “I know this jacket is not the style you want, sir, but would you like to try it for size? It happens to be the color you mentioned.” Few men have patience with this treatment, and the usual response is: “This is the right color and may be the right size, but I should be wasting my time and yours by trying it on.”
Now how does a woman go about buying clothes? In almost every respect she does so in the opposite way. Her shopping is not often based on need. She has never fully made up her mind what she wants, and she is only “having a look round”. She is always open to persuasion; indeed she sets great store by what the saleswoman tells her, even by what companions tell her. She will try on any number of things. Uppermost in her mind is the thought of finding something that everyone thinks suits her. Contrary to a lot of jokes, most women have an excellent sense of value when they buy clothes. They are always on the lookout for the unexpected bargain. Faced with a roomful of dresses, a woman may easily spend an hour going from one rail to another, to and fro, often retracing her steps, before selecting the dresses she wants to try on. It is a laborious process, but apparently an enjoyable one. Most dress shops provide chairs for the waiting husbands.The underlined sentence “the price is a secondary consideration” in the first paragraph means when a man is shopping ______.
| A．he buys good quality things, so long as they are not too dear |
| B．he buys whatever he likes without considering its value |
| C．he does not mind how much he has to pay for the right things |
| D．he often buys things without giving the matter proper thought. |
What does a man do when he can not get exactly what he wants?
| A．He buys a similar thing because of the color he wants. |
| B．He usually does not buy anything. |
| C．At least two of his requirements must be met before he buys. |
| D．So long as the style is right, he buys the thing. |
What is the most obvious difference between men and women shoppers?
| A．Men do not try clothes on in a shop while women do. |
| B．Women bargain for their clothes, but men do not. |
| C．The time they take over buying clothes. |
| D．Men go shopping based on need, but women never. |
We now think of chocolate as sweet, but once it was bitter. We think of it as a candy, but once it was a medicine. Today, chocolate can be a hot drink, a frozen dessert, or just a snack. Sometimes it's an ingredient (配料) in the main course of a meal. Mexicans make a hot chocolate sauce called mole and pour it over chicken. The Mexicans also eat chocolate with spices (香料) like chili peppers.
Chocolate is a product of the tropical cacao tree. The beans taste so bitter that even the monkeys say "Ugh!" and run away. Workers must first dry and then roast the beans. This removes the bitter taste.
The word "chocolate" comes from a Mayan word. The Mayas were an ancient people who once lived in Mexico. They valued the cacao tree. Some used the beans for money, while others crushed them to make a drink.
When the Spaniards came to Mexico in the sixteenth century, they started drinking cacao too. Because the drink was strong and bitter, they thought it was a medicine. No one had the idea of adding sugar. The Spaniards took some beans back to Europe and opened cafes. Wealthy people drank cacao and said it was good for the digestion.
In the 1800s, the owner of a chocolate factory in England discovered that sugar removed the bitter taste of cacao. It quickly became a cheap and popular drink. Soon afterwards, a factory made the first solid block of sweetened chocolate. Later on, another factory mixed milk and chocolate together. People liked the taste of milk chocolate even better.
Besides the chocolate candy bar, one of the most popular American snacks is the chocolate chip cookie. Favorite desserts are chocolate cream pie and, of course, an ice cream sundae with hot fudge sauce.The main topic of the passage is _________.
| A．the different tastes of chocolate |
| B．the origin of the word “chocolate” |
| C．the medical effects of chocolate |
| D．the production and development of chocolate |
The Spaniards think that cacao was a medicine because_____
| A．it was strong and bitter. |
| B．it was good for digestion. |
| C．it cured man's diseases. |
| D．it was a kind of drink for good health. |
Which is the right time order of the events regarding chocolate?_______
a. Chocolate became a cheap and popular drink in England.
b. A factory made the first solid block of sweetened chocolate.
c. The Spaniards started drinking cacao.
d. It was found that sugar removed the bitter taste of cacao.
e. A factory mixed milk and chocolate together.
| A．a-b-c-d-e | B．c-d-e-b-a | C．c-d-a-b-e | D．c-d-b-e-a |
It can be inferred from the passage that _____.
| A．Mexicans like chocolate very much |
| B．chocolate can be a hot drink, a frozen dessert, or a candy bar |
| C．chocolate is a product of the cacao tree |
| D．people liked the taste of chocolate mixed with milk |
A machine which makes water out of air could become the greatest household invention since the microwave． Using the same technology as a dehumidifier (除湿器)， the Water Mill is able to create a ready supply of drinking water by getting it from a limitless source－the air． The company behind the machine says not only does it offer all alterative to bottled water in developed countries，but it is a solution for the millions who face a daily water shortage．
The machine works by drawing in damp air through a filter(过滤器) and over a cooling element which changes it into water droplets．It can produce up to 12 liters a day．The Water Mill will also produce more water when storms pass over, as the humidity（湿度）in the air increases．In keeping with its ecodevelopment，the machine uses the same amount of electricity as three light bulbs．
Inventor Jonathan Ritchey said：“The demand for water is off the chart．People are looking for freedom from water distribution systems that are shaky and unreliable”．
The machine，which is about 3 feet wide，is likely to cost￡800 when it goes on sale here in the spring．Its maker, Canadian firm Element Four, estimates that a liter of water will cost around 20 pence to produce．
Environmentalists claim half the world’s population will face water shortage because of climate change by 2080．One in five humans is said to lack access to safe drinking water．
The Water Mill is not effective in areas with below about 30 percent relative humidity, but with average relative humidity in England of more than 70 percent that won’t be much of an issue here.According to the author, the biggest advantage of the machine is its ______．
| A．little power use | B．unlimited source | C．proper size | D．high production |
We can conclude from the passage that the machine________．
| A．can be used everywhere |
| B．has not been on sale |
| C．will replace the water distribution system |
| D．will solve the problem of water shortage |
The underlined phrase “off the chart” in the passage means ________
| A．record-breaking． | B．urgent． | C．unbelievable． | D．amazing． |
What would be the best title for this passage?________
| A．Microwave for Household Use | B．Filter to Draw in Damp Air |
| C．Mode Dehumidifier on Sale | D．Machine to Make Water out of Air |
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