Puzzled by this strange natural phenomenon, t...

Puzzled by this strange natural phenomenon, the scientists started to explore every _______ they knew to figure it out.

A. impression　　 B. intention　　　 C. avenue　　 　 D. design

高三英语单项填空中等难度题查看答案及解析

Scientists have been puzzled by the phenomenon that migrating birds fly not just in groups all the time, but in "V" formations and they have tried to figure out what benefit birds get from this particular formation. Now, a research group from University of London may have found the answer ― migrating birds fly in a "V" to save energy, according to a study published in the journal Nature.

When a bird flaps(振翅) its wings, it stirs the air around it and causes it to move indifferent directions. Scientist found in the study that the air creates an upward-moving wave at the tips of the wings, which means that if a bird flies around the wingtips of another bird, it can get a boost（抬高） from the rising air and therefore use less energy to stay in the air.

Apart form the "free ride" strategy, scientists were also surprised to observe that migrating birds timed their wing beats and adjusted their positions in a very precise way to maximize the lifting effect while avoiding areas where the air move downward.

"They're able to sense what's going on from the bird in front, where this 'good air' is coming from and now how to position themselves perfectly in it," lead researcher Steven Portugal told BBC.

In fact, the "V" formation has long thought to help birds fly more efficiently(效率搞地). A previous study showed that birds' heart rates went down when they were flying together in a "V" formation. Jet fighters were also found to be able reduce their energy use by up to 18% by staying near the wingtips of other jet fighters. Both of these findings led scientists to suspect that the "V" formation had an efficiency purpose, but until now they still lack proof.

"For scientists, the new study provides an insight into an interesting natural phenomenon. But it could mean even more for aircraft companies — helping them understand how they can imitate that with their plane formations to save fuel, said Portugal."

1.What is the author's purpose in writing this article?

A. To explain how birds benefit from migration.

B. To introduce how migrating birds find their way.

C. To tell some applications of migrating birds' "V" formations.

D. To report new findings about migrating birds' "V" formations.

2. According to the recent study, when birds migrate         .

A. they don't change their lead birds during the whole journey

B. they fly in "V" formations to protect themselves against enemies

C. they form the shape of a "V" to make best use of the lifting effect

D. the air they stir around makes it hard for the birds behind to fly fast

3.What is the significance of the new study according to this article?

A. It might inspire aircraft companies to think of ways to improve efficiency.

B. It has proved that the "V" formation can improve in efficiency in many fields,

C. It has led scientists to discover that birds' heart rates go down when they fly in a "V".

D. It shows that the best formation of jet fighters in battle should be a "V" formation.

4. The underlined word "imitate" in the last paragraph most probably means "            ".

A. use                    B. copy                C. change                D. learn

高三英语阅读理解中等难度题查看答案及解析

Have you ever noticed this phenomenon? Sometimes Chinese English teachers are puzzled by such questions, "Could you please give me some advice　 　　 how to improve my reading comprehension?"

Actually, many of the teachers can't give their students 　　 effective way to deal with reading. Anyway, they often simply say, "Read　 　　 and practise more, and you will get more experience in reading comprehension. " Frankly, these teachers' good suggestions are only helpful to arouse (激起) students' interest in reading　 　　　 not helpful to deal with the questions in the examinations of reading comprehension. Personally, 　　　 think the skill for reading comprehension should be based on the knowledge of English writing.　　 　 the English passages are written under some rules or principles, the science of reading and understanding may have a close relationship with writing. Reading comprehension can't be independent 　　　 the knowledge of

writing. So to do better in reading comprehension 　　　 ever, we should learn the knowledge of writing, study how questions are designed and the relationship between questions and the reading materials.

高三英语语法填空困难题查看答案及解析

Have you ever noticed this phenomenon? Sometimes Chinese English teachers are puzzled by such questions, ¨Could you please give me some advice 1.how to improve my reading comprehension?"

Actually, many of the teachers can't give their students2.effective way to deal with reading．Anyway, they often simply say, “Read and you will get more experience in reading comprehension．3. and practice more, " Frankly, these teachers' good suggestions are only helpful to arouse c镁次起） students' interest in reading 4. not helpful to deal with the questions in the examinations of reading comprehension．Personally, _5.think the skill for reading comprehension should be based on the knowledge of English writing．6. or principles, the science of reading the English passages are written under some rules and understanding may have a close relationship with writing．Reading comprehension can't be independent7.　 the knowledge of writing．So to do better in reading comprehension8. ever, knowledge of writing, study how questions are designed and the questions and the reading materials．

高三英语其他题中等难度题查看答案及解析

Strange ice rings in Siberia’s Lake Baikal have puzzled scientists for decades, but now the mystery apparently has been solved. The answer: the rings are caused by warm, circular currents of water under the ice, called eddies (漩涡).

The eddies’ strong currents melt the ice at the edge, but weaker ones keep the center frozen. “Results of our field surveys show that there are warm eddies that circulate in a clockwise (顺时针的) direction under the ice cover,” said Alexei Kouraev, a hydrologist at the University of Toulouse, in a NASA statement. “In the eddy center, the ice does not melt — even though the water is warm — because the currents are weak,” he said. “But on the eddy boundary, the currents are stronger, and warmer water leads to rapid melting.”

During field work, Kouraev and his colleagues drilled holes near ice rings and set sensors capable of measuring the temperature and salinity (盐浓度) of the water to a depth of 700 feet. They found that the water in the eddies was 2 to 4 ℉ warmer than the surrounding water.

Most of the rings appear in March or April and have a width of about 3 to 4 miles — too big to recognize from the ground but easily seen from satellites above. Some rings were ephemeral while others lasted for weeks or even months.

Lake Baikal is the world’s largest and deepest freshwater lake, according to Gizmodo. It’s home to many varieties of fish not seen anywhere else in the world, and even a population of freshwater seals.

Researchers are still investigating what causes Baikal’s eddies but think it’s likely because of wind patterns, rivers that flow into the lake and the shape of the lake’s coastline and bottom.

1.Which word can best replace the underlined word “ephemeral” in paragraph 4?

A.Steady. B.Current.

C.Fundamental. D.Temporary.

2.Why is the ice in the center of ice rings frozen while that at the edge is melted?

A.Because the center of ice rings is 2 to 4℉ warmer than the edge.

B.Because the currents in the center are less powerful.

C.Because it is too wide to be recognized or melted.

D.Because water in the center circulates in a clockwise direction.

3.Which of the following statements about Lake Baikal’s eddies is TRUE?

A.They are caused by hot and circular currents under the ice.

B.The ice in the center of Lake Baikal’s eddies melts faster than that of the edge.

C.Researchers are uncertain about the exact reason of the eddies’ existence.

D.Lake Beikal’s eddies can only be measured at the depth of 700 feet.

4.What maybe the best title for the passage?

A.What’s causing the giant ice rings in Siberia?

B.The mystery of the eddies' in the Lake Baikal uncovered.

C.The largest and deepest freshwater lake — Lake Baikal.

D.Why does the edge of an ice ring melt faster?

高三英语阅读理解中等难度题查看答案及解析

Thousands of years ago people discovered the phenomenon by chance, and this was _____ the idea of the compass first came from.

A. how                B. what         C. where        D. that

高三英语单项填空中等难度题查看答案及解析

This is the main use that the scientists make______ natural resources.

A. in　　 　　　　　　 B. up of

C. from　　 　　　　　　 　 D. of

高三英语单项填空中等难度题查看答案及解析

The Island Rule is one of the best explanations scientists could give to the observable phenomenon that animals and humans have evolved (演变) depending on the resources available in their habitat (栖息地). Through time, scientists have noticed through fossil (化石) records that some large animals from mainland habitats have dwarf (矮小的) versions in bland habitats.

A report from BBC described the existence of what scientists call “hobbit island” off a small island somewhere in Indonesia. It was given such a name because fossil records of tiny, humanlike creatures have been found in the region. What they called as “hobbits” or “Homo Floresiensis”, are only as tall as one meter and arc small versions of early human species with tinier brains.

Though scientists cannot perfectly trace the origin of the “Homo Floriensis”, they believe that they arc human relatives, but it is the “island life” that has caused them to evolve as they have. Scientists have noticed through fossil records and existing organisms (有机体) today that it seems if large animals grow small in islands while small animals grow large in larger islands.

In theory, animal and human bodies have adjusted to the available food and fresh water in their habitats. Since there is no opportunity for them to leave their island, they might as well adapt.

New York Magazine explained that islands usually have fewer predators (捕食者) than mainland ecosystems. However, it is the lack of resources that cause the death of many animals. As a means of natural adaptation, the bodies of these animals have evolved smaller than their ancestors, making their bodies require fewer resources.

A report from Web Ecoist listed down a few examples of animals that have shrunk significantly compared with their ancestors. Some of these include the Bali tiger as small as leopards (豹).

1.How did the name “hobbit island” come from?

A. Scientists discovered dwarf people living on the island.

B. One meter tall human being made a living on these islands.

C. Scientists found human species with tinier brains on an island.

D. Evidences showing tiny, human-like creatures on the island were found.

2.What do you know about “Homo Floricnsis”?

A. They used to only live somewhere in Indonesia.

B. They were the earliest ancestor of human beings.

C. They look small compared with normal humans.

D. They gradually grew larger on the larger islands.

3.According to New York Magazine, 　　　　 .

A. animals on island lack enough food to live on

B. many animals died off for no apparent reason

C. too many predators will do damage to the ecosystem

D. predators make island animals turn smaller

4.What can be inferred from the text?

A. More predators can help animals grow stronger and larger.

B. Bali tiger turns small because of adaptation to the environment.

C. More food resources should be provided lo islands.

D. Animals on mainland arc fiercer than those on islands.

高三英语阅读理解中等难度题查看答案及解析

Crown shyness(树冠羞避) is a mysterious natural phenomenon in which the crowns of some tree species do not touch each other, but get separated by a gap clearly visible from ground level. The effect usually occurs between trees of the same species, but has also been observed between trees of different species.

There are many theories going around, most of which make sense, but no one has been able to prove without the shadow of a doubt why some trees avoid touching each other.

In his 1955 book Growth Habits of the Eucalypts, Australian forester M.R. Jacobs writes that the growing tips of the trees are sensitive to abrasion(擦伤), which results in crown shyness phenomenon. This theory was also supported by Dr. Miguel Franco. Some experiments have shown that if trees displaying crown shyness are artificially prevented from swinging in the wind and touching each other, they gradually fill up the gaps between them.

But while the above theory is arguably the most widespread, it’s certainly not the only one. Some scientists have suggested that crown shyness is a mechanism to stop the spreading of leaf-eating insects. These pests have been known to work together and create structures that extend up to 10 cm off of tree branches in order to reach other plants, so the gaps are the trees’ natural defense method.

One Malaysian scholar studied many trees, but found no traces of abrasions, despite their clear crown shyness. Instead, he suggests that the growing tips of the trees were sensitive to light levels and stopped growing when they got too close to other trees. Plants are able to sense how close they are to other plants and in order to get more light, they give off some chemical element to stop other trees from growing too close.

Whatever the reason, one thing is for sure: plants are more intelligent than people used to think.

1.What can we know about crown shyness?

A. It can cause abrasion between trees.

B. It only happens between the same species.

C. It has been discovered for only half a century.

D. No agreement has been reached about its real cause.

2.What will happen if trees showing crown shyness are stopped from swinging?

A. The trees will stop growing and even die.

B. The gaps between the trees will grow wider.

C. The crown shyness phenomenon will disappear.

D. The gaps between the trees will remain the same.

3.What’s tree’s reaction when attacked by pests according to the text?

A. Swinging less in the wind

B. Leaving space between their crowns

C. Spreading their branches and leaves

D. Stopping growing for a period of time

4.Which statement might the Malaysian scholar agree with?

A. Trees have special ways to attack others.

B. Some insects stop trees growing too close.

C. Trees compete with their neighbors for light.

D. Trees won’t touch each other to avoid diseases.

高三英语阅读理解中等难度题查看答案及解析

It’s a natural phenomenon. The minute you think you want to buy something new, you go online to read reviews about it. Not only is this done with shopping, it’s also done for movies to see , restaurants to go to and almost everything that is worth having an opinion on. The concept of writing down a review for all to see is something that has caused the birth of reviews sites. These are sites where people post reviews on other people, services, businesses, products and more.

In some cases you have professionals do the review and in some other cases you will have the average person write it up. Review sites have a number of ways in which they can gain revenue for themselves in the form of advertising. In some cases, a business can pay his way through to a better listing spot. This does not mean that a positive review will be promoted where it is not warranted (担保).

Review sites are largely a public forum and it is not necessary for people to reveal their identity. Since people are anonymous (匿名的) and sign up access is open to all, there are chances that reviews will be planted or will be negatively written simply to discredit a particular product or service.

There is a lot of criticism towards these websites since they do nothing to control the kind of entries made or the source of these entries. On the other hand, there are professional review sites. These people are accountable for each of their reviews. Any doubts you have will be addressed personally by the one writing the review. Such sites work on much better principles allowing for a fair opinion.

Considering they have a better reputation, they are aware of some the latest products that are released worldwide. This gives you a better chance of finding reviews of the latest product. While a review site will help you narrow down your choice, it by no means should influence your final decision. That is based entirely on the way you see fit.

1.Nowadays, before buying something, people usually ________.

A．ask the opinion of others                 B．surf famous review sites.

C．ignore topics of review sites.               D．read reviews on the Internet.

2.The underlined word “revenue” in Paragraph 2 probably means”______”.

A．the announcement posted by sites

B．the income earned from sales or services

C．the freedom of writing reviews

D．the program made by advertisement companies

3.What do we know about the professional reviews sites?

A．The reviews on the sites are written mainly by professors.

B．Those who write the reviews on the sites are serious sometimes.

C．The reviewer addresses your doubt personally for you.

D．The reviewers on the sites are ready to write to you if you like.

4.This passage was written mainly to tell us________.

A．to make good use of review sites

B．to consult something with reviewers

C．not to make a decision before reading reviews

D．not to believe some review sites

高三英语阅读理解中等难度题查看答案及解析