Memory, they say, is a matter of practice and exercise. If you have the wish and really made a conscious（自觉的）effort, then you can quite easily improve your ability to remember things. But even if you are successful, there are times when your memory seems to play tricks on you.
Sometimes you remember things that really did not happen. One morning last week, for example, I got up and found that I had left the front door unlocked all night, yet I clearly remember locking it carefully the night before.
Memory “trick” work the other way as well. Once in a while you remember not doing something, and then find out that you did. One day last month, for example, I was sitting in a barber（理发师）shop waiting for my turn to get a haircut, and suddenly I realized that I had got a haircut two days before at the barber shop across the street from my office.
We always seem to find something funny and amusing（有趣的）in incidents caused by people’s forgetfulness or absent-mindedness. Stories about absent-minded professors have been told for years, and we never got tired of hearing new ones. Unfortunately, however, absent-mindedness is not always funny. There are times when “trick” of our memory can cause us great trouble.
【小题1】If you want to have a good memory, .

Scientists have developed a water treatment system that they say is a powerful but simple way to save lives. Four grams of chemicals can treat ten liters of dirty water for a low cost, about ten cents.
Experts say infections from dirty water kill several thousand children in developing countries every day. The Procter and Gamble company has been developing the "PUR Purifier of Water" system since 1995. The company has been working with the United States Centers for Disease control and Prevention(C.D.C.).
C.D.C. researchers tested it in Guatemala, Pakistan and Kenya. Procter and Gamble researcher Greg Allgood says cases of diarrhea(腹泻) in those studies fell by about 50 percent. Researchers from Johns Hopkins University in Maryland tested the system at a refugee camp in Liberia. Mr. Allgood says that study found a reduction of more than 90 percent. Use of the system is being expanded worldwide.
The treatment contains bleach(漂白剂) to kill disease-causing organisms. It also contains something that dirt and other particles stick to. Mr. Allgood says the chemicals can remove lead and other dangerous metals and even agricultural poisons like D.D.T.
Mr. Allgood heads the Children's Safe Drinking Water program at Procter and Gamble. He says about forty million packets of the treatment have been given to countries for free. They have been used in emergencies and in areas with limited supplies of clean water.
Clean water is a limited resource in many parts of the world. Delegates from about 130 nations attended the Fourth World Water Forum last month in Mexico City. Scientists, policy experts and others discussed ways to provide clean water to the world’s poor. Organizers say more than twenty percent of the world population lacks clean drinking water. The final declaration did not go so far as to declare water a human right. But it did say that governments, not private companies, must take the lead in improving the public’s ability to have clean water.
46. What is mainly talked about in this passage?
A. Water pollution around the world.
B. The causes of diarrhea in African countries.
C. A newly developed water treatment system.
D. The Fourth World Water Forum in Mexico City.
47. Which of the following developed the water treatment system?
A. The US Centers for Disease Control and Prevention.
B. The Procter and Gamble Company and C.D.C.
C. The Children’s Safe Drinking Water Program.
D. Johns Hopkins University.
48. Which of the following about the new water treatment system is NOT true?
A. It is effective but very expensive.
B. It was tested in Guatemala, Pakistan and Kenya.
C. It is being expanded worldwide.
D. It can remove dangerous metals in the water.
49. Which of the following shows that the shortage of clean water is a serious problem?
A. Forty million packets of the treatment have been given to countries for free.
B. Delegates from about 130 nations attended the Fourth World Water Forum.
C. Four grams of chemicals can treat liters of dirty water for a low cost.
D. Infections from dirty water kill several thousand children every day.
50. The best title for this article is ______.
A. A Small Packet of Chemicals, a Big Effect on Dirty Water
B. The Procter and Gamble Company and C.D.C.
C. The Shortage of Clean Water                           
D. How to Cure Diarrhea

October 15th is Global Handwashing Day．Activities are planned in more than twenty countries to get millions of people in the developing world to wash their hands with soap．
Experts say people around the world wash their hands but very few use soap at so-called critical moments．These include after using the toilet, after cleaning a baby and before touching food．
Global Handwashing Day is the idea of the Public-private Partnership for handwashing with soap．The goal, they say, is to create a culture of handwashing with soap．The organizers say all soaps are equally effective at removing disease-causing germs．They say the correct way to wash is to wet your hands with a small amount of water and cover them with soap．Rub it into all areas, including under the fingernails．Then, wash well under running water．Finally, dry your hands with a clean cloth．
The Partnership says soap is important because it increases the time that people spend washing．Soap also helps to break up the dirt that holds most of the germs．And it usually leaves a pleasant smell, which increases the chances that people will wash again．
It also says that washing hands with soap before eating and after using the toilet could save more lives than any medicine．It could help reduce cases of diarrhea, which is the second leading cause of child deaths, killing more than one and a half million children a year, by almost half．
【小题1】What does the author intend to tell us in the passage?

Bad teeth can be painful -- and worse. They can even be deadly. Infections (感染) of the gums (牙龈) and the teeth can cause bacteria (细菌) to go into the blood system. Those bacteria can increase the chance of a heart attack and worsen the effects of other diseases. And adults are not the only ones at risk.
For example, in 2007, doctors in the Washington area said a boy died when a tooth infection spread to his brain. They said it might have been prevented had he received the dental care (牙齿保健) he needed. He was twelve years old.
Experts at the National Institutes of Health say good dental care starts at birth. Breast milk, they say, is the best food for the healthy development of teeth. Breast milk can help slow the growth of bacteria and acid production in the mouth.
But dentists say a baby's gums and early teeth should be cleaned after each feeding. Use a cloth with a little warm water. Do the same if a baby is fed with a bottle. Experts say if you decide to put your baby to sleep with a bottle, only give the child water.
When baby teeth begin to appear, you can clean them with a wet toothbrush. Dentists say it is important to find soft toothbrushes made especially for babies and to use them very gently.
The use of fluoride (氟化物) to protect teeth is common in many parts of the world. For example, it is often added to drinking water supplies. The fluoride mixes with enamel (珐琅质) , the hard surface on teeth, to help prevent holes from forming.
【小题1】Which of the following can be used as the title of the passage?

Claude and Louris are “giraffes”. So are police officers Hankins and Pearson. These men and women don’t look like giraffes; they look like you and me. Then, why do people call them “giraffes”?

A giraffe, they say, is an animal that sticks its neck out, can see places far away and has a large heart. It lives a quiet life and moves about in an easy and beautiful way. In the same way, a “giraffe” can be a person who likes to “stick his or her neck out” for other people, always watches for future happenings, has a warm heart for people around, and at the same time lives a quiet and beautiful life himself or herself.

“The Giraffe Project” is a 10-year-old group which finds and honors “giraffes” in the US and in the world. The group wants to teach people to do something to build a better world. The group members believe that a person shouldn’t draw his or her head back; instead, they tell people to “stick their neck out” and help others. Claude and Louris, Hankins and Pearson are only a few of the nearly 1,000 “giraffes” that the group found and honored.

Claude and Louris were getting old and they left their work with some money that they saved for future use. One day, however, they saw a homeless man looking for a place to keep warm and they decided that they should “stick their neck out” and give him some help. Today, they lived in Friends’ House, where they invite twelve homeless people to stay every night.

Police officers Hankins and Pearson work in a large city. They see crimes every day and their work is sometimes dangerous. They work hard for their money. However, these two men put their savings together and even borrowed money to start an educational center to teach young people in a poor part of the city. Hankins and Pearson are certainly “giraffes”.

1. Which of the following is true?

   A. Some of the people around us look like giraffes.

B. Giraffes are the most beautiful animal in the world.

   C. “Giraffes” is a beautiful name for those who are ready to help other people.

D. A “giraffe” is someone who can stick his neck out and see the future.

2. “The Giraffe Project” is a group _____.

  A. of police officers                  B. which appeared ten years ago

  C. of ten-year-old children             D. which takes care of children

3. People call Claude and Hankins “giraffes” because they _____.

  A. do what is needed for a good world          B. are not afraid of dangerous work

  C. found a home for some homeless people      D. made money only for other people

4. What does “The Giraffe Project” do?

  A. It tells people how to live a quiet life.

  B. It helps the homeless and teaches the young people.

  C. It tries to find 1,000 warm-hearted people in the US.

  D. It shows people what their duty is for a better world.

5. The underlined word “crime” in the last paragraph has the similar meaning to ____.

A. mistake       B. happiness     C. failure      D. wrongdoing