A new study says one part of the human brain may become smaller as the result of a condition known as jet lag. Jet lag results from flying long distances in an airplane. People with jet lag may feel extremely tired for several days. They may also have problems thinking clearly and remembering.

Recently a researcher at the University of Bristol in Britain reported the findings of his jet lag study, which involved twenty young women who worked for international airlines. They had served passengers on airplanes for five years. These flight attendants flew across many countries and at least seven time zones. In the study, the flight attendants had different amounts of time to recover from jet lag. Half the women spent five days or fewer in their home areas between long flights The other half spent more than fourteen days in their home areas.

The researcher took some saliva from the women's mouths to measure levels of a hormone(荷尔蒙) that increases during stress (紧张). He tested them to see if they could remember where black spots appeared on a computer screen. And he took pictures of their brains to measure the size of the brain's temporal lobes (脑叶).

It was found that the women who had less time between flights had smaller right temporal lobes. This area of the brain deals with recognizing and remembering what is seen. The same group performed worse and had slower reaction times on the visual memory test. And their saliva samples showed higher levels of stress hormones.

The researcher believes the brain needs at least ten days to recover after a long trip. He says airline workers told him their ability to remember got worse after working on planes for about four years. Other studies have shown that increased feelings of stress can cause a loss of cells in the part of the brain that controls memory.

Scientists say more tests are needed to study the effects of jet lag on the brain. They want to find out if too much jet lag could permanently (永久性的) affect memory.

According to the text, jet lag _________.

A. can cause difficulties in speaking

B. can make people feel tired for a few weeks

C. can be only found in flight attendants

D. can be caused by flying over several time zones

It can be inferred from the text that _________.

A. the conclusion is refused by many scientists

B. scientists fear that this research is not done properly

C. every scientific conclusion needs the support from many tests

D. the women who were examined in the research were not healthy

From the result of the research we can see that _________.

A. the women who have longer rest at home show better memory

B. the women who fly in short time have smaller right temporal lobes

C. the women who have longer flights fail the memory test

D. the women who rest more than 14 days produce less hormones

What is the subject discussed in the text?

A. The cause of jet lag.      B. A story of a group of flight attendants.

C. The importance of having enough rest after flights.

D. A research about the effects of jet lag on the brain.

A new study warns that about thirty percent of the world's people may not have enough water by the year 2025.

   A private American organization called Population Action International did the new study. It says more than three-hundred-thirty-five-million people lack enough water now. The people live in twenty-eight countries. Most of the countries are in Africa or the Middle East.

   P-A-I researcher Robert Engelman says by the year 2025, about three-thousand-million people may lack water. At least 18 more countries are expected to have severe water problems. The demand for water keeps increasing. Yet the amount of water on Earth stays the same.

   Mr. Engelman says the population in countries that lack water is growing faster than in other parts of the world. He says population growth in these countries will continue to increase.

   The report says lack of water in the future may result in several problems. It may increase health problems. Lack of water often means drinking waters are not safe. Mr. Engelman says there are problems all over the world because of diseases, such as cholera, which are carried in water. Lack of water may also result in more international conflict. Countries may have to compete for water in the future. Some countries now get sixty percent of their fresh water from other countries. This is true of Egypt, the Netherlands, Cambodia, Syria, Sudan, and Iraq. And the report says lack of water would affect the ability of developing to improve their economies. This is because new industries often need a large amount of water when they are beginning.

   The Population Action International study gives several solutions to the water problem. One way, it says, is to find ways to use water for more than one purpose. Another way is to teach people to be careful not to waste water. A third way is to use less water of agriculture.

   The report also says long-term solutions to the water problem must include controls on population growth. It says countries cannot provide clean water unless they slow population growth by limiting the number of children people have.

           are expected to have severe water problems by the year 2025.

A. 18 countries                             B. No countries

    C. 46 countries                            D. 28 countries

All the following are true except            .

    A. New industries need a lot of water

    B. There are solutions to the water problem

    C. Egypt now has enough fresh water

    D. Lack of water may cause conflict between countries

It can be learned that           .

  A. The ability of developing has nothing to do with lack of water.

    B. . It is not known whether diseases have something to do with lack of water

    C. Lack of water may also result from international conflict

    D There is connection between providing clean water and slowing population growth

The best title of the passage would be          .

  A. World Water Shortage                       B. Population and Water

    C. World Conflict                           D. Diseases and Water

As any homemaker who has tried to keep order at the dinner table knows, there is far more to a family meal than food. Sociologist Michael Lewis has been studying 50 families to find out just how much more.
Lewis and his co-workers carried out their study by videotaping the families while they ate ordinary meals in their own homes. They found that parents with small families talk actively with each other and their children. But as the number of children gets larger, conversation gives way to the parents’ efforts to control the loud noise they make. That can have an important effect on the children." In general the more question-asking the parents do, the higher the children’s IQ scores," Lewis says. "And the more children there are, the less question-asking there is."
The study also provides an explanation for why middle children often seem to have a harder time in life than their siblings(兄弟，姐妹). Lewis found that in families with three or four children, dinner conversation is likely to center on the oldest child, who has the most to talk about, and the youngest, who needs the most attention. “Middle children are invisible,” says Lewis. “When you see someone get up from the table and walk around during dinner, chances are that it’s the middle child.” There is, however, one thing that stops all conversation and prevents anyone from having attention: “When the TV is on,” Lewis says, “dinner is a non-event(扫兴的事).”
【小题1】The writer’s purpose in writing the text is to _________.

As any homemaker who has tried to keep order at the dinner table knows，there is far more to a family meal than food. Sociologist(社会心理学家)Michael Lewis has been studying 50 families to find out just how much more.
Lewis and his co－workers carried out their study by videotaping(录像) the families while they ate ordinary meals in their own homes. They found that parents with small families talk actively with each other and their children. But as the number of children gets larger，conversation gives way to the parents’ efforts to control(控制)the loud noise they make. That can have an important effect on the children. “In general the more question－asking the parents do，the higher the children’s IQ scores.”
Lewis says，“And the more children there are，the less question－asking there is.”
The study also provides an explanation for why middle children often seem to have a harder time in life than their siblings(兄弟姐妹)．Lewis found that in families with three or four children，dinner conversation is likely to center on the oldest child，who has the most to talk about，and the youngest，who needs the most attention. “Middle children are invisible(看不见的)，”says Lewis.“ When you see someone get up from the table and walk around during dinner，chances are it’s the middle child.” There is，however，one thing that stops all conversations and prevents anyone from having attention：“When the TV is on，” Lewis says，“ dinner is a non－event.”
【小题1】The writer’s purpose in writing the text is to ________.

As for visiting Walt Disney World. People usually have trouble in arranging. The following will give you some practical suggestions on paying a valuable visit to the famous park.
When to go?
While it’s always busy, Disney World is slightly slower between mid-January and March. It’s summer when the visitors , combined with the heat and humidity(潮湿)， are crowded. Your best choice is either early in the morning or late in the day--- often you can enjoy more rides in the first or last two hours of the day than you can the entire rest of the day combined.
Where to stay?
The question: to stay on Disney World Resort property or not. Disney World offers three resort pricing: Deluxe(豪华的), Moderate, and Value, with good facilities and in-hotel attractions. That said, they all offer “Extra Magic Hours”(early access to the theme parks), guaranteed entry when the parks are over-crowded, and frequent shuttle service to the many attractions. Off-property hotels will have shuttle transfers, but often at less regular intervals(间歇)，wasting more time in transport. You’ll also need a rental car, which adds to the expense, making up for saving in the hotel rate. The “Magic Your Way Package” is a good value if you have a large family.
What to do?
Make use of the “Fast Pass” , which , for no extra cost, allow you to insert your entrance ticket into a particular machine at the attraction and receive a schedule ride time a little later on. For example, use your Fast Pass ticket at a ride just before getting lunch. Once you’re done eating, you can return to the ride and jump right on during the busiest time of day. At the Animal Kingdom, the animals are most active either early or late in the day, so plan accordingly. Thankfully this is fit for the least busy times of day in the park. Study the map of the park the night before to plan your visit. You’ll save time by knowing where things are and where you’re headed.
【小题1】Visitors who use Fast Pass tickets ________