In the long discussion of water on the Moon, a new study contradicts(与……相矛盾)) some recent reports that say the Moon had water at the time of its formation. A group of researchers reported in the journal Science that when the Moon was created, some 4.5 billion years ago, there was not much hydrogen(氢气) on it, and therefore no water.
The researchers surveyed and evaluated this by analyzing chlorine isotopes(氯同位素) found in lunar rock samples from Apollo missions. The range of chlorine isotopes in lunar samples was 25 times that found in samples from Earth.
If the Moon had significant levels of hydrogen, as Earth did, this range would have been far less, said Zachary D Sharp, a scientist in the Department of Earth and Planetary Sciences at the University of new Mexico and the study’s lead authour.
The chlorine would have stuck together with hydrogen, forming compounds like hydrogen chloride, and escaped from the Moon’s surface, he said. The abundance of chlorine indicates a lack of hydrogen and water.
“ The amount of water on the Moon was too low for life to possibly have existed there,” he said.
Most scientists believe the Moon was formed when a large object stuck
Earth, breaking off a chunk(a vast piece) that has since orbited Earth.
On Earth, goes one theory, water was released as steam form molten basalts(玄武岩) over time, eventually forming bodies of water.
“An understading of whether the Moon was dry or wet will help us understand how water appeared on Earth,” Dr Sharp said. A new study indicates that _____ on the moorn.
| A.there is plenty of water | B.water is unlikely to exist |
| C.water existed in the past | D.there is a little water now |
The author would like to tell us ______ through the sixth paragraph.
| A.why there is no water on the Moon | B.how the Moon was formed |
| C.when the Earth struck the Moon | D.where the Moon orbited |
Which is NOT true according to the passage?
A. Zachary D. Sharp, a scientist of New Mexico was in charge of the new study.
B. Chlorine isotopes in lunar samples are 25 time larger than those on the Earth.
C. The more aboundant chloride, the shorter hydrogen and water.
D. The new study is benificial to understand how water appeared on Earth. What can we learn from the passage?
| A.There is enough water on the Earth. |
| B.Hydrogen chloride easily escaped from the Moon’s surface. |
| C.The Earth had significant levels of hydrogen. |
| D.Water on the Earth is directly from molten basalts. |
Facial expressions carry meaning that is determined by situations and relationships. For example, in American culture (文化) the smile is in general an expression of pleasure. Yet it also has other uses. A woman's smile at a police officer does not carry the same meaning as the smile she gives to a young child. A smile may show love or politeness. It can also hide true feelings. It often causes confusion (困惑) across cultures. For example, many people in Russia smiling at strangers in public to be unusual and even improper. Yet many Americans smile freely at strangers in public places (although this is less common in big cities). Some Russians believe that Americans smile in the wrong places; some Americans believe that Russians don't smile enough. In Southeast Asian culture, a smile is frequently used to cover painful feelings. Vietnamese people may tell a sad story but end the story with a smile.
Our faces show emotions (情感), but we should not attempt to "read" people from another culture as we would "read" someone from our own culture. The fact that members of one culture do not express their emotions as openly as do members of another does not mean that they do not experience emotions. Rather, there are cultural differences in the amount of facial expressions permitted. For example, in public and in formal situations many Japanese do not show their emotions as freely as Americans do. When with friends, Japanese and Americans seem to show their emotions similarly.
It is difficult to generalize about Americans and facial expressiveness because of personal and cultural differences in the United States. People from certain cultural backgrounds in the United States seem to be more facially expressive than others. The key is to try not to judge people whose ways of showing emotion are different. If we judge according to our own cultural habits, we may make the mistake of "reading" the other person incorrectly.
| 1. |
What does the smile usually mean in the U.S.?
|
| 2. |
The author mentions the smile of the Vietnamese to prove that smile can.
|
| 3. |
What should we do before attempting to "read" people?
|
| 4. |
What would be the best title for the test?
|
You may think that sailing is a difficult sport, but it is really not hard to learn it. You do not need to be strong. But you need to be quick. And you need to understand a few basic rules about the wind.
First, you must ask yourself, “Where is the wind coming from? Is it coming from ahead or behind or from the side?” You must think about this all the time on the boat. The wind direction tells you what to do with the sail.
Let’s start with the wind blowing from the behind. This means the wind and the boat are going in the same direction. Then you must always keep the sail outside the boat. It should be at a 90° angle (角度) to the boat. Then it will catch the wind best.
If the wind is blowing from the side, it is blowing across the boat. In this case, you must keep the sail half way outside the boat. It should be at a 45° angle to the boat. It needs to be out far enough to catch the wind, but it shouldn’t flap (摆动). It shouldn’t look like on a flagpole. If it is flapping, it is probably out too far, and the boat will slow down.
Sailing into the wind is not possible. If you try, the sail will flap and the boat will stop. You may want to go in that direction. It is possible, but you can’t go in a straight line. You must go first in one direction and then in another. This is called tacking. When you are tacking, you must always keep the sail inside the boat.What should you consider first while sailing?
| A.Sailors’ strength. | B.Wave levels. |
| C.Wind directions. | D.Size of sails. |
What does the word “It” underlined in Paragraph 4 refer to?
| A.The boat. | B.The wind. | C.The sail. | D.The angle. |
What do you have to do when sailing against the wind?
| A.Move in a straight line. | B.Allow the sail to flap. |
| C.Lower the sail. | D.Tack the boat. |
Where can you probably find the text?
| A.In a popular magazine. | B.In a tourist guidebook. |
| C.In a physics textbook. | D.In an official report. |
Cold weather can be hard on pets, just like it can be hard on people. Sometimes owners forget that their cats are just as used to the warm shelter (住所) as they are. Some owners will leave their animals outside for a long period of time, thinking that all animals are used to living outdoors. This can put their pets in danger of serious illness. There are things you can do to keep your animal warm and safe.
Keep your pets inside as much as you can when the weather is bad. If you have to take them out, stay outside with them. When you’re cold enough to go inside, they probably are too. If you must leave them outside for a long time, make sure they have a warm, solid shelter against the wind, thick bedding, and plenty of non-frozen water.
If left alone outside, dogs and cats can be very smart in their search for warm shelter. They can dig into snow banks or hide somewhere. Watch them closely when they are left outdoors, and provide them with shelter of good quality. Keep an eye on your pet’s water. Sometimes owners don’t realize that a water bowl has frozen and their pet can’t get anything to drink. Animals that don’t have clean and unfrozen water may drink dirty water outside, which may contain something unhealthy for them.What do we learn about pets from Paragraph 1?
| A.They are often forgotten by their owners. |
| B.They are used to living outdoors. |
| C.They build their own shelter. |
| D.They like to stay in warm places. |
Why are pet owners asked to stay with their pets when they are out in cold weather?
| A.To know when to bring them inside. |
| B.To keep them from eating bad food. |
| C.To help them find shelters. |
| D.To keep them company. |
If pets are left on their own outdoors in cold weather, they may ___.
| A.run short of clean water |
| B.dig deep holes for fun |
| C.dirty the snow nearby |
| D.get lost in the wild |
What is the purpose of this text?
| A.To solve a problem. |
| B.To give practical advice. |
| C.To tell an interesting story. |
| D.To present a research result. |
Are you looking for some new and exciting places to take your kids (孩子) to? Try some of these
places:
l Visit art museums. They offer a variety of activities to excite your kids' interest. Many offer
workshops for making land-made pieces, traveling exhibits, book signings by children's
favorite writer, and even musical performances and other arts
l Head to a natural history museum. This is where kids can discover the past from dinosaur(恐龙) models to rock collections and pictures of stars in the sky. Also, ask what kind of workshops and educational programs are prepared for kids and any special events that are coming up.
l Go to a Youtheater. Look for one in your area offering plays for child and family visitors. Pre-show play shops are conducted by area artists and educators where kids can discover the secret about performing arts. Puppet(木偶)making and stage make-up are just a couple of the special offerings you might find.
l Try hands-on science. Visit one of the many hands-on science museums around the country. These science play-lands are great fun for kids and grown-ups alike. They'll keep your child mentally and physically active the whole day through while pushing buttons, experimenting, and building. When everyone is tired, enjoy a fun family science show, commonly found in these museums.If a child is interested in the universe, he probably will visit .
| A.a Youtheater |
| B.an art museum |
| C.a natural history museum |
| D.a hands-on science museum |
What can kids do at a Youtheater?
| A.Look at rock collections. |
| B.See dinosaur models. |
| C.Watch puppet making. |
| D.Give performances. |
What does "hands-on science" mean in the last paragraph?
| A.Science games designed by kids. |
| B.Learning science by doing things. |
| C.A show of kids' science work. |
| D.Reading science books. |
Where does this text probably come from?
| A.A science textbook. |
| B.A tourist map. |
| C.A museum guide. |
| D.A news report. |
Grown-ups are often surprised by how well they remember something they learned as children but have never practiced ever since. A man who has not had a chance to go swimming for years can still swim as well as ever when he gets back in the water. He can get on a bicycle after many years and still ride away. He can play catch and hit a ball as well as his son. A mother who has not thought about the words for years can teach her daughter the poem that begins "Twinkle, twinkle, little star" or remember the story of Cinderella or Goldilocks and the Three Bears.
One explanation is the law of overlearning, which can be stated as follows: Once we have learned something, additional learning trials(尝试) increase the length of time we will remember it.
In childhood we usually continue to practice such skills as swimming, bicycle riding, and playing baseball long after we have learned them. We continue to listen to and remind ourselves of words such as "Twinkle, twinkle, little star" and childhood tales such as Cinderella and Goldilocks. We not only learn but overlearn.
The multiplication tables(乘法口诀表) are an exception to the general rule that we forget rather quickly the things that we learn in school, because they are another of the things we overlearn in childhood.
The law of overlearning explains why cramming(突击学习)for an examination, though it may result in a passing grade, is not a satisfactory way to learn a college course. By cramming, a student may learn the subject well enough to get by on the examination, but he is likely soon to forget almost everything he learned. A little overlearning, on the other hand, is really necessary for one's future development.
| 1. |
What is the main idea of paragraph 1?
|
| 2. |
The author explains the law of overlearning by.
|
| 3. |
According to the author, being able to use multiplication tables is.
|
| 4. |
What does the word "they" in Paragraph 4 refer to?
|
| 5. |
What is the author's opinion on cramming?
|