A three-year independent investigation into the September 11, 2001 attack on the Pentagon has yielded new eyewitness evidence which, according to the Southern California-based researchers who conducted the investigation conclusively (and unfortunately), establishes as a historical fact that the violence which took place in Arlington that day was not the result of a surprise attack by suicide hijackers, but rather a military black operation involving a carefully planned and skillfully executed deception."

A CNN Reporter at the scene states that there is no evidence that a 757 hit the Pentagon.

　  What hit the Pentagon? A Boeing 757 loaded with passengers and fuel right? Who was on Flight 757? According to the Flight Information there were No Arabs on it. That makes me wonder if Flight 757 actually existed at all.

　　From the pictures and the videos, people can find that there are several doubtful points that need to be taken into consideration, for example the marker line on the grass in the satellite and ground pictures, the different colors of the smoke, the hole which the plane impacted, and the standing pylons (架线塔).

　　Also, from the comparison of the different pictures, people can find some other strange points. For example, the gear (齿轮) is not the matching one. The wreckage of the plane is not the one from the American Airlines. The glass on the pavement of the pole is another doubtful point. The last thing that need considering is about the collapse. One of the gif video shows the plane impacting the Pentagon. The only problem with this video footage is that it has been altered (改变) and can not be fully trusted.

　　These crash photos and videos shown here clearly have been doctored (篡改) and don't even match the physics of what happened. So where is the real video? It leaves me many questions. Is this a missile? It is a real enigma.

1.Where can you possibly read this article?

2.What the word “yielded” mean in the first sentence?

3.Which of the following doubtful points is not mentioned in the passage?

4. What is the author’s attitude towards the 911 investigation?

It is natural that children are curious (好奇的) about the world around them. For example, they want to know how their hearts beat. They want to know why the ocean water tastes salty.

　　As children grow up, they become curious about different kinds of things. When they are babies, they are interested in the parts of their bodies and in the smiles of their mothers. They become interested in the physical world around them: the plants, the animals, the sky. Later, they become interested in the things that people have made: wheels, bicycles, cars. And when they are adults, their curiosity continues. Sometimes this curiosity leads to a career (生涯、职业) in science.

　　Scientists spend their lives trying to find out about the world．Those who work with the earth sciences study the earth, the oceans, and the skies. Other scientists who study living things work with the biological sciences. A third group of scientists study the physical sciences, e. g. physics, chemistry .

　　These scientists have already discovered a lot about our world．For example, they tell us why your heart beats fast when you run. They say that when you are quiet, your heart normally beats sixty-five or seventy-five times a minute. Your heart is a pump (泵) that pumps blood to all parts of the body. The blood carries oxygen and nutrition. When you run, your muscles work very hard and use the nutrition that the blood carries to them. The muscles need oxygen, too . So your brain sends a signal to the heart. The signal means that the muscles need more nutrition and oxygen. Then the heart beats fast and sends blood quickly to the muscles. It may beat 90 to 140 times a minute.

　　Of course, scientists cannot answer all of our questions. If we ask, “Why does the ocean water taste salty” scientists will say that the salt comes from rocks. When a rock gets very hot or very cold, it cracks. Rain falls into cracks. The rain then carries the salt into the earth and into the rivers. The rivers carry the salt into the ocean. But then we ask , “What happens to the salt in the ocean? The ocean does not get saltier every year.” Scientists are not sure about the answer to this question.

　　We know a lot about our world, but there are still many answers that we do not have, and we are curious.

According to the passage, which of the following statements is true?

　   A．People are curious in the same way.

　   B．People in different countries are interested in different things.

　   C．Men and women are curious about different things.

　   D．People of different ages are interested in different things

Scientists who work with the biological sciences study____.

       A．the earth , the oceans and the sky   B．man-made things

       C．plants and animals   D．ocean water

When you run, your muscles need ____.

A．more nutrition and oxygen    B．more signals    C．more salt   D．water

A rock cracks _____.

A．in wet regions                                  B．in dry regions

C．at very high or very low temperatures     D．when salty water falls in

     Apparently，we are safe neither at home nor in the business office.We use water in both places，but the research shows that chemicals added to our local water supply to kill harmful bacteria can have unwanted side effects.These chemicals can cause potential harm through drinking and in seemingly harmless activities as cleaning one’s house.They are released(set free)from water by daily actions like water running out of tap，spraying from garden pipes，or splashing in dishwashers and washing machines.As the water is moving.these chemicals are released into the air and then breathed in. Once inside our bodies, they start to affect our health.

　　Does this mean we should stop bathing? No, say the scientists, but we should put all pollution into perspective. Activities at home such as the burning of coal, cooking oil, or even candles release carbon monoxide and particulates such as cigarette ashes which have been proven as harmful to health as working or living near heavy traffic. New tugs, bedding, and even clothing give off that“new smell, ”which is a sure sign of chemicals. In the office, newly applied paint, newly purchased telephones and other telecommunications equipment, and computers release polluting chemicals, too. As offices and homes often have inadequate ventilation (通风), these chemicals can build up to become health problems. Their poisonous effects are only now being slowly recognized.

　　These facts suggest that, at a minimum, proper airing of newly purchased goods with an obvious chemical smell is a wise warning. Home and office windows should be opened during good weather. Even one’s car needs to be ventilated as well while in the garage.

　　We need further research to understand better other potential health dangers, too. For example, the effects of overcrowding of schools (carbon dioxide build-up ), the factory work environment ( an endless list of potentially dangerous substances ), and even home heating and cooling (the air conditioner may be our enemies, not our friends) have only recently started to come to light. Until we understand the effects of our new technological environment better, we can only hope that“there is no place like home.”

What is the main idea of the first paragraph?

　　A.The air we breathe in is harmful.

B.Chemicals are released in the running water.

C.Chemicals are added to the drinking water.

　　D. The water in everyday use is unsafe.

.In Paragraph 2, the underlined sentence means that .

　　A. homes and offices should be aired often

　　B. any pollution should be taken into consideration

　　C. bathing should be done with caution

　　D.we should prevent any pollution from doing harm to us

What is the purpose of the passage?

　　A.To call on us to guard our water.

　　B.To show us that no place is like home.

　　C.To make us aware of the pollution around us.

　　D.To argue that neither homes nor offices are safe.