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Ever wonder how much a cloud weighs? What about a hurricane? A meteorologist has done some estimates and the results might surprise you.
Let's start with a very simple white puffy cloud — a cumulus cloud(积云). How much does the water in a cumulus cloud weigh? Peggy LeMone, senior scientist at the National Center for Atmospheric Research in Boulder, Colorado, did the numbers. "The water in the little cloud weighs about 550 tons," she calculates. "Or if you want to convert it to something that might be a little more meaningful … think of elephants."
The thought of a hundred elephants-worth of water suspended in the sky begs another question — what keeps it up there?
"First of all, the water isn't in elephant sized particles(微粒), it's in tiny tiny tiny particles," explains LeMone. And those particles float on the warmer air that's rising below. But still, the concept of so much water floating in the sky was surprising even to a meteorologist like LeMone. "I had no idea how much a cloud would weigh, actually, when I started the calculations," she says.
So how many elephant units of water are inside a big storm cloud—10 times bigger all the way around than the "puffy" cumulus cloud? Again, LeMone did the numbers: About 200,000 elephants.
Now, ratchet up the calculations for a hurricane about the size of Missouri and the figures get really massive. "What we're doing is weighing the water in one cubic meter theoretically pulled from a cloud and then multiplying by the number of meters in a whole hurricane," she explains.
The result? Forty million elephants. That means the water in one hurricane weighs more than all the elephants on the planet. Perhaps even more than all the elephants that have ever lived on the planet.
The weight of      is NOT mentioned in the passage.

A.a cumulus cloud B.a tornado C.a hurricane D.a storm cloud

How did Peggy LeMone feel about the result of her calculations?

A.She found it not convincing.
B.She thought it needed further calculations.
C.She was quite surprised at it.
D.She considered the calculations inaccurate.

What can be inferred from the passage?

A.A storm cloud weighs about 200,000 elephants.
B.The water in a hurricane weighs more than that in any other kind of cloud.
C.There are less than forty million elephants living on the earth.
D.The water in the cloud is in very tiny partials.
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The purpose of the passage is to _______.

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D.sell the four books to students.

More and more people are taking their iPads to bed with them to surf the web, check facebook or send e-mails before switching off the light. But researchers are warning that the blue light their screens give off can stop users getting a good night’s sleep. That is because this type of light is similar to daylight, convincing the brain that it is still daytime. Blue light prevents the production of a brain chemical called melatonin, which helps us fall asleep. By contrast, light which is more orange or red does not prevent melatonin production, perhaps because our brains recognize it as a cue that the day ends.
Scientists have known for years that staring at screens late in the evening can affect sleep ---- they are television screens, computer screens or mobile phone screens. However, because mobiles and iPads are by nature portable ---- not to say addictive ---- more people are taking them into the bedroom. Users also tend to hold them much closer to their eyes than a computer or television screen.
Researchers are warning that looking at iPad displays for more than two hours leads to lower natural melatonin levels as the devices give off blue light. They say, “Turning off the devices at night is the final solution. But if you have to use these devices at night, dim the display to cut down irritation of the eyes and limit the time you spend on them before bed.”
They wrote in the journal Applied Ergonomics(应用人类工程学) that iPad makers should adjust the spectral power distribution(光谱功率分布) of the devices so that they affect the sleep patterns of users less.
It is not just a good night’s sleep that could be harmed by too much late night screen time. Researchers know that long-term harm to sleep patterns can lead to an increased risk of obesity and even cancers.
What’s the main idea of the passage?

A.Scientists are warning that blue light is bad for our health.
B.People should limit the use of electronic devices
C.Using iPads before bed can cause a poor night’s sleep.
D.Looking at screens of iPads increase chances of sleeplessness.

Will Nanfang University of Science and Technology in Shenzhen announce a new beginning for China’s higher education reform? It’s too early to answer. But its presence is challenging the Ministry of Education. Even without the approval of the ministry it seems that the school is determined to move forward and enroll 50 students, so-called child prodigies(奇才), to begin classes on March l, 2011.On graduating in 2015, these students will receive a diploma unauthorized by the Ministry of Education----unlike the students of their age from the state-run universities.
The school is committed to modeling itself on Hong Kong University of Science and Technology, but if the government will not approve the school, the situation could cause a lot of trouble for those 50 students if they want to do graduate studies at other higher learning institutions. Other schools could turn their applications down for their unauthorized diplomas.
The difficulties, however, have not frightened students and their parents away. On Dec.18, 2010 more than 1,000 students and their parents visited Nanfang University of Science and Technology for interviews.
Private investment marks the school out from other higher learning institutions in the nation. Not a penny comes from the government. So the government will have no voice in how the school will be run.
The Ministry of Education has published a comprehensive plan for education reform and development between 2011 and 2020.The goal is to make China’s higher education internationally competitive. To accomplish this goal, the government should have the courage to let the educators who have big ideas try them out. The ministry should have applauded the independence. The school in Shenzhen has shown and encouraged more to do likewise.
Education reform in China has reached a new and crucial stage. Nanfang University of Science and Technology has a long way to go to prove itself competitive rather than a diploma mill.
What is the best title of the passage?

A.University of New Style.
B.China’s Education Reform.
C.Modeling Hong Kong University.
D.Authorized or Not?

It’s not easy being a teenager---nor is it easy being the parent of a teenager.You can make your child feel angry, hurt or misunderstood by what you say without realizing it yourself.It is important to give your child the space he needs to grow while gently letting him know that you’ll still be there for him when he needs you.
Expect a lot from your child, just not everything.Except for health and safety problems,such as drug use or careless driving, consider everything else open to discussion.If your child is unwilling to discuss something, don’t insist he tell you what’s on his mind.The more you insist,the more likely that he’ll calm up.Instead, let him attempt to solve things by himself.At the same time, remind him that you’re always there for him should he seek advice or help.Show respect for your teenager’s privacy(隐私).Never read his mail or listen to personal conversations.
Teach your teenager that the family phone is for the whole family.If your child talks on the family’s telephone for too long, tell him he can talk for l5 minutes, but then he must stay off the phone for at least all equal period of time.This not only frees up the line so that other family members can make and receive calls, but teaches your teenager moderation(节制).Or if you are open to the idea, allow your teenager his own phone that he pays for with his own pocket money or a part-time job.
The main purpose of the text is to tell parents_________.

A.how to get along with a teenager
B.how to help a teenager grow up
C.how to understand a teenager
D.how to respect a teenager

The term, culture shock, describes the anxiety produced when a person moves to a completely new environment. This term expresses the lack of direction, the feeling of not knowing what to do, and not knowing what is appropriate or inappropriate. The feeling of culture shock generally sets in after the first few weeks of coming to a new place.
We can describe culture shock as the physical and emotional discomfort one suffers when coming to live in another country or place. Often, the way that we lived before is not accepted as or considered as normal in the new place. Everything is different, for example, not speaking the language, not knowing how to use banking machines and so forth.
Although one can experience real pain from culture shock, it is also an opportunity for resetting one' s life objectives. It is a great opportunity for learning and acquiring new viewpoints. Culture shock can make one develop a better understanding of oneself.
Culture shock has many stages. The first stage is called the "honeymoon" stage. The new arrival may feel excited as everything is new.
In the second stage, a person may encounter some difficult times in daily life. For example, communication difficulties may occur such as not being understood. There may be feelings of discontent, anger, sadness, and feeling incompetence. This happens when a person is trying to adapt to a new culture. Transition (过渡) between the old methods and those of the new country is a difficult process and takes time to complete.
The third stage is characterized by gaining some understanding of the new culture. One may start to feel a certain psychological balance. The new arrival may start to have a feeling of direction and want to belong.
In the fourth stage, the person realizes that the new culture has good and bad things to offer. The person has a more solid feeling of belonging and starts to set goals for living.
The fifth stage is called the " re-entry shock". This occurs when a return to the
country of origin is made. One may find that things are no longer the same. For example, some of the newly acquired customs are not in use in the old culture.
Many factors (因素) contribute to the length and effects of culture shock. For example, the individual's state of mental health, type of personality, previous experiences, familiarity with the language, and level of education. So the five stages are present at different times and each person has their own way of reacting.
The main purpose of the passage is to________

A.discuss and clarify B.argue and advise
C.introduce and explain D.compare and evaluate

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