Before a new type of airplane goes into service, every part of it is tested again and again. But there are two tests that are more important than all the others.
The first is called the “tank test”. A modern airplane must fly very high in the sky. Air must be pumped into the plane so that the passengers can breathe. The metal structure (结构) of the plane has to be very strong for this reason. When the plane is filled with air, the air presses against the skin of the plane inside. The pressure (压力) on a small window is like a huge foot that is trying to get out. If a small part of the plane were to fail, the plane would explode in the sky. To test the structure of the plane, the plane is lowered into a huge tank or container of water. Then it is filled with air. The pressure inside the plane is greater than it ever will be when it is high up in the air. Finally, there is an explosion. This does not cause so much damage inside the water tank as it would anywhere else. Engineers can discover which part of the plane has broken. Then that part is made stronger,
The most dangerous test happens when the new plane is going through test flights in the air. The test pilot must find out exactly what happens when the engines (发动机) are all shut off at once. The plane begins to fall like a stone. It is the pilot’s job to find out how he can get control of the plane again. These two tests are examples of how planes are made safe before they ever carry passengers.
68. By doing the “tank test”, the engineers can find out ________.
A. the power of the airplane engines B. the amount of air in the plane
C. the strength of the plane structure D. the pressure inside and outside the plane
69. What will happen to the plane under the “tank test”?
A. It will be tested by pilots. B. It will be broken.
C. It will be made stronger. D. It will be filled with water.
70. According to the text. why are test flights most dangerous?
A. Too much air may get into the plane. B. The plane may explode in the air.
C. The pilot may lose control of the plane. D. The engines may be damaged.
71. What might be the most suitable title for the text?
A. How Airplanes Are Made and Tested B. Two Important Tests on Airplanes
C. The Importance of Flying Safely D. The Danger of Testing Airplanes
The greatest artistic creative geniuses I've ever seen, have been those who can turn garbage into art. Not just gluing together junk, but really making waste into something unique, cool, and well, something you, d put into your home for instance. There's something to be said about recycling of those items we commonly throw away.
The ability to take trash and garbage and turn it into art, or something intriguing that is fascinating to look at is a skill all of its own. I have often said that the true geniuses of our time, that is to say the creative genius artists of our era, are those who can do this-creating art that can command a high price tag from junk. 0ver the years while traveling through the United States I had stopped into museums in many parts of the country.
Some of the best art I've ever seen in my life has come from garbage, trash, or junk that has been reworked and recycled into something spectacular. Best of all the artists don't spend much on material costs, therefore it is mostly profitable. In fact they are using their minds to do a lot with very little. Just think if we all used our minds to do this, how little we might actually throw away, and how more efficiently we could run our factories, production, and even households.
After all, anything that is not used is waste, and it is thrown away. It ends up in a landfill, or a dump somewhere, and eventually it decays in the soil, causing perhaps ground water pollution. However, if we can rework these items for a couple of more rounds, and waste less, then we are providing efficiency for our civilization, and that's a good thing. Any artist who can do this is not only one caring the environment, but also one with humanity, and using his brain power and creative genius to make us all better. What would be the best title for the passage?
| A．Garbage in art out |
| B．Recycle garbage in a new way |
| C．A new kind of art |
| D．A new way to protect the environment |
The author believes the art work created from junk __________.
| A．is not suitable to be put in our home |
| B．is of little value |
| C．can be of great value |
| D．will end up in landfills |
What do we know from the third paragraph?
| A．The author can't afford good art from garbage. |
| B．Art made from garbage doesn't cost much in material. |
| C．The author collects a lot of art from garbage. |
| D．The author thinks it's easy to make art from garbage. |
We learn from the last paragraph that __________.
| A．real artists are those with humanity |
| B．creating art from garbage can also help the environment |
| C．there is no good way to deal with waste today |
| D．a great amount of waste has been reused by artists |
What's the author's attitude towards the artists who turn garbage into art?
| A．Neutral. | B．Pitiful. |
| C．Doubtful. | D．Supportive. |
Twelve years ago, a young traveler named Rhett Butler from San Francisco, California, visited the Sabah rain forest on Malaysian Borneo. In one area of the rain forest, he watched a bird flying through the trees. The beautiful sight left quite an impression on him. But weeks later, back home, Rhett Butler got the news that trees had been cut down in the area he visited.
That experience led Rhett Butler to begin writing a book about rainforests and the threats to their existence. But he did not publish the book. Instead, in 1999，he used his research for the book to create a website. The site is Mongabay, com. His purpose was to inform the public about tropical rain forests. But the subject quickly developed. As a former businessman , he became a respected writer of science and environmental stories.
The popularity of Mongabay. com attracted advertisers. Small ads on the site pay for its operations. Mongabay. com has grown and led to other sites. For example, there is a site for children which is called kids, Mongabay. com. Another one, Wild Madangascar. org, is also about the island nation that Rhett Butler calls his favorite place.
To keep his website going, he travels around the world on several major trips each year. His working tools are a laptop computer, cameras and sometimes diving equipment. He often calls on experts for information. For example, he interviewed Alison Jolly, a top experts on lemurs (狐猴）. He interviewed Rodney Jackson, a biologist who established the Snow Leopard Conservancy.
Stories like these have made Mongabay a favorite place on the Internet for researchers, students and teachers. In April, Time, com named it one of the fifteen top climate and environment websites in the world. What's the main idea of the passage?
| A．Rhett Butler and his website. |
| B．Rainforest on Malaysian Borneo. |
| C．How Rhett Butler protected rare animals. |
| D．How Rhett Butler made his website popular. |
Rhett Butler didn't publish his book about rain forests because __________
| A．making websites earns more money than writing books |
| B．he didn't want to become a writer |
| C．the book was not about rain forest protection |
| D．he wanted to use the information to create a website |
Which of the followings is NOT true about the Mongabay. com?
| A．It was set up in 1999. |
| B．It attracted many advertisers. |
| C．At least two related websites grew from it. |
| D．Rhett Butler made a lot of money from it. |
To keep his website going, Rhett Butler __________.
| A．kept visiting the rain forest |
| B．traveled around and interviewed experts |
| C．raised rare snow leopards |
| D．made a great number of advertisements |
We can learn from the passage that __________.
| A．Mongabay. com was loved by researchers as well as students |
| B．kids. Mongabay. com has many stories written by kids |
| C．Wild Madagascar, org is better known than Mongabay. com |
| D．Rodney Jackson was once a businessman |
None of our early ancestors could digest milk as adults because their bodies never had to—milk drinking simply wasn't an option. As people began to extract milk from animals, though, some people developed the ability to keep drinking it throughout their lives.
Scientists now know of a milk-related mutation (变异）in our genes—the chemical instructions for life that we carry in almost every cell in our bodies. People who have a mutated form of one particular gene can drink milk just fine. People without the mutation tend to get sick from milk.
To figure out where, and possibly why, milk drinking started, some scientists have been looking at who has the milk-digesting mutation today. Patterns are striking.
Most adults in Northern and Central Europe are able to digest milk—and they do. Cheese and butter and other dairy products are popular in countries such as Sweden, Denmark, Germany and England. Because European settlers dominated North America, most people here can handle milk just fine, as well. That may explain why ice cream is such a popular dessert in the United States.
In much of Africa, Asia and South America, on the other hand, people tend to avoid dairy products because they lead to diarrhea(腹泻)and other stomach problems (That's why you won't typically find cheese on the menu at a Chinese, Japanese or Ethiopian restaurant. ). Native Americans are also unable to digest milk.
Based on these genetic patterns, scientists have long thought that milk drinking started in Northern Europe, where dairy is an institution and the milk-digesting mutation is everywhere.
A recent study painted a different picture. With a computer medal, Thomas and colleagues looked at the spread of the milk-drinking mutation, farming and other related factors. Working back-ward, the scientists concluded that the first milk-drinkers lived in Central Europe around what's now Hungary about 7，500 years ago. The practice didn't start farther north, as scientists had thought be-fore. Which of the following is the proper order of events according to the passage?
a. Their children were able to digest milk as adults.
b. They got sick from the milk.
c. Some people got a mutation in their genes.
d. Some people tried drinking milk from animals.
e. Some people started to drink milk from animals on a regular basis.
| A．c→d→b→e→a | B．d→e→b→c→a |
| C．d→b→e→c→a | D．e→d→b→c→a |
Most people in the USA can digest milk because __________
| A．they have strong stomachs |
| B．their ancestors were Europeans |
| C．that's where milk drinking started |
| D．farmers raise a lot of cows there |
Which of the following is LEAST likely to appear on the menu in a Japanese restaurant?
| A．Butter. | B．Vinegar. | C．Fish. | D．Beef. |
Which of the followings is the author most likely to agree with?
| A．Milk drinking first started in Northern Europe. |
| B．Milk drinking first started in Central Europe. |
| C．North American Indians were able to digest milk. |
| D．Dairy products are very popular in North Korea. |
The main focus of the scientists' research was __________.
| A．mutation of human genes |
| B．development of the human stomach |
| C．why milk drinking started |
| D．where milk drinking first started |
A jobless man wanted very much to have the position of " office boy" at Microsoft. The HR manager interviewed him and then watched him cleaning the floor as a test. " You have passed the test，" he said. "Give me your e-mail address and I'll send you the form to fill in and the date when you may start. " The man replied，"But I don't have a computer, neither an e-mail. " " I'm sorry，"said the HR manager. " If you don't have an e-mail, that means you are not living. And anyone who isn't living cannot have the job. "
The man left with no hope at all. He didn't know what to do with only $ 10 in his pocket. He thought and thought. Then he went to the supermarket and bought 10 kilos of tomatoes. He sold the tomatoes from door to door. In less than two hours, he had 20 dollars. He repeated the operation three times, and started to go early every day, and returned home late. Shortly, he bought a cart, then a truck, then he had his own fleet of delivery vehicles (运货车队）. Five years later, the man was one of the biggest food retailers(零售商)in the US.
One day, one of his friends asked him for his e-mail. He said，"I haven't got one. " His friend couldn't believe his ears. " Can you imagine what you could have been if you had an e-mail?" The man thought for a while and replied，" Yes, I'd be an office boy at Microsoft ！ " What did the man do for the test?
| A．He sent e-mails. | B．He did the cleaning. |
| C．He sold computers. | D．He filled in forms. |
The man didn't get the job because he __________.
| A．disliked such a job |
| B．didn't pass the test |
| C．didn't have an e-mail |
| D．knew nothing about computers |
The man __________ after he left Microsoft.
| A．went to look for another job |
| B．asked for food from door to door |
| C．thought of an idea to make money |
| D．bought a computer and got an e-mail |
Why could the man become one of the biggest food retailers in the US?
| A．Because he had many friends to help him. |
| B．Because he was smart and worked very hard. |
| C．Because he had his own fleet of delivery vehicles. |
| D．Because he wanted to show Microsoft he was living. |
What does the story want to tell us?
| A．Computers are very important in our daily life. |
| B．Everyone can make a lot of money with only $ 10. |
| C．The HR manager didn't find the ability of the man. |
| D．Nothing in the world is impossible if we work hard. |
Most American kids love Halloween treats, but a bucket of Halloween candy can be a dentist's nightmare. Some parents try to get rid of half of the candy after their children go to bed, but dentists say parents also need to separate the good kinds of treats from the bad.
It is not exactly what a child eats that truly matters, but how much time it stays in his mouth. According to pediatric dentist Dr. Kaneta Lott, the most damaging stuff is something that is sticky or very hard and thus stays in the mouth for a long time. This is because we all have bacteria in our mouths. When we eat, the bacteria take our food as their food and produce an acid that destroys the surface of the teeth, causing cavities to form. The longer the food stays in the mouth, the more likely cavities will develop. Therefore, potato chips are worse than candy because they get stuck between teeth. For the same reason, raisins and crackers are not the best choice. Hard candies take a long time to consume and are also a bad choice for Halloween treats.
If children really love candy, dentists recommend that they eat chocolate instead. Unlike hard candies, chocolate dissolves quickly in the mouth. Besides, chocolate contains tannins, which help to kill some of the bacteria in the mouth. But no matter what a child eats, brushing after eating is still the best way to fight cavities. What is the main purpose of this passage?
| A．To discuss how cavities can be treated. |
| B．To point out the problems with Halloween celebrations. |
| C．To tell parents what sweets are less damaging to their children's teeth. |
| D．To teach parents the meaning of Halloween candies for their children. |
Why are hard candies especially bad for teeth?
| A．They may break the child's teeth. |
| B．They contain too much sugar. |
| C．They help bacteria to produce tannins， |
| D．They stay in the mouth for a long time. |
According to the passage, which of the following is a better choice for Halloween treats?
A. Chocolate. B. Crackers.
C, Raisins. D. Potato chips. According to the passage, which of the following is true of tannins?
| A．They are produced when the bacteria digest the food. |
| B．They help to get rid of some bacteria in the mouth. |
| C．They help chocolate to dissolve more quickly. |
| D．They destroy the surface of the teeth. |