Heat might explain why we lost our fur and no...

Heat might explain why we lost our fur and now strike an upright and slim pose(姿势).

If our ancestors lived somewhere really hot, the theory goes, it would have made sense for us to lose body hair, start sweating more, become slender(修长的) and even walk upright—to create distance between our bodies and the hot ground.

A new study supports the theory that heat helped drive human evolution(进化), by showing that a key source of human evolution in East Africa has indeed been really hot for at least four million years.

“It’s something that’s been hard to get at,” said Ben Passey, a geochemist(地球化学家) at Johns Hopkins University in Baltimore. “It’s nice to say that these body features would be advantageous to live in hot and open environments. But was it actually hot and open?”

To find out, Passey and his colleagues analyzed dated soil examples from the Turkana Basin, a well-studied region in Kenya and Ethiopia that contains lots of fossils(化石) from our human and pre-human ancestors. In particular, they looked at weighted carbon and oxygen atoms, called isotopes(同位素).

Their results, published in the Proceedings of the National Academy of Sciences, showed that dirt in the Turkana Basin has remained above about 85 degrees Fahrenheit with spikes(尖状物) above 95 degrees Fahrenheit over the past four million years. Since soil absorbs heat from the air, it means that the region has been really hot for a really long time.

“There is no question that the results are fascinating,” said Harvard anthropologist(人类学家), Daniel Lieberman, who studies how and why the human body looks the way it does.

For one thing, at some point we developed a unique ability to control our body temperature while running, which might have helped people catch prey(猎物) in hot and dry conditions. “The hotter it is, the more humans have an advantage over other mammals, especially when running.”

“No one knows for sure when we lost our fur,” he added. “But this paper provides strong evidence that the right climatic conditions were present for a long time.”

1.What is the main idea of the text?

A. Heat made humans lose their fur.　　 B. Heat caused humans to walk upright.

C. Heat helped the evolution of humans.　　 D. Heat affected the height of our ancestors.

2.The main aim of Passey’s study is to find out__________.

A. why Africa is suitable for humans to live in

B. how many types of fossils there are in the Turkana Basin

C. what the climatic conditions were like four million years ago

D. whether East Africa is the key source of human evolution

3.According to Daniel Lieberman, ___________.

A. the result of Passey’s study is not satisfactory

B. controlling the body temperature helped catch prey

C. a hot climate was not helpful for human evolution

D. humans ran faster than other animals in winter

4.Which of the following statements about East Africa is TRUE?

A. The high temperature in this area has been stable for a long time.

B. It was one of the toughest places for human ancestors to bear.

C. Few people studied the Tukana Basin before Passey.

D. The soil has remained over 95 degrees F for a long time.

高二英语阅读理解中等难度题查看答案及解析

We __________ our lives had it not been for the policeman.

A. would have lost     B. should lose       C. might lose        D. could have lost

高二英语单项填空简单题查看答案及解析

Unless we spend money to spot and prevent asteroids now，one might crash into Earth and destroy life as we know it，say some scientists.

Asteroids are bigger versions of the meteoroids(流星)that race across the night sky. Most orbit the sun far from Earth and don't threaten us. But there are also thousands whose orbits put them on a collision course with Earth.

Buy $ 50 million worth of new telescopes right now. Then spend $ 10 million a year for the next 25 years to locate most of the space rocks. By the time we spot a fatal one，the scientists say，we'll have a way to change its course.

Some scientists favor pushing asteroids off course with nuclear weapons. But the cost wouldn't be cheap. Is it worth it? Two things experts consider when judging any risk are: 1) How likely the event is; and 2) How bad the consequences if the event occurs. Experts think an asteroid big enough to destroy lots of life might strike Earth once every 500,000 years. Sounds pretty rare-but if one did fall，it would be the end of the world. “If we don't take care of these big asteroids，they'll take care of us,” says one scientist. “It's that simple.”

The cure，though，might be worse than the disease. Do we really want fleets of nuclear weapons sitting around on Earth? “The world has less to fear from doomsday(毁灭性的) rocks than from a great nuclear fleet set against them，” said a New York Times article.

1.What does the passage say about asteroids and meteoroids?

A. They are heavenly bodies different in composition.

B. They are heavenly bodies similar in nature.

C. There are more asteroids than meteoroids.

D. Asteroids are more mysterious than meteoroids.

2. What do scientists say about the collision of an asteroid with Earth?

A. It is very unlikely but the danger exists.

B. Such a collision might occur once every 25 years.

C. Collisions of smaller asteroids with Earth occur more often than expected.

D. It's still too early to say whether such a collision might occur.

3. What do people think of the suggestion of using nuclear weapons to alter the course of asteroids?

A. It sounds practical but it may not solve the problem.

B. It may create more problems than it might solve.

C. It is a waste of money because a collision of asteroids with Earth is very unlikely.

D. Further research should be done before it is proved applicable.

4.We can conclude from the passage that ________ .

A. while pushing asteroids off course nuclear weapons would destroy the world

B. asteroids racing across the night sky are likely to hit Earth in the near future

C. the worry about asteroids can be left to future generations since it is unlikely to  happen in our lifetime

D. workable solutions still have to be found to prevent a collision of asteroids with Earth.

5.Which of the following best describes the author's tone in this passage?

A. Optimistic.          B. Critical.       C. Objective.      D. Subjective.

高二英语阅读理解简单题查看答案及解析

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

Why do we play sports? You might say “to get exercise” and you'd be right. To have fun? That's true, too. But there's more. 　　 1.　　 According to the Women's Sports Foundation, girls who play sports get a lot more than just fit.

Girls who play sports do better in school. You might think that playing sports will take up all your study time. 　 2.　 Exercise improves learning, memory, and concentration, which can give active girls an advantage in the classroom.

Girls who play sports learn teamwork and goal-setting skills. 　 3.　 When you work with coaches, trainers, and teammates to win games and achieve goals, you're learning how to be successful. Those skills will serve you well at work and in family life.

Sports are good for a girl's health. In addition to being fit and keeping a healthy weight, girls who play sports are also less likely to smoke. And later in life, girls who exercise are less likely to get osteoporosis(骨质疏松症).

Playing sports improves self-confidence. 　 4.　　 Why? It builds confidence when you know you can practice, improve, and achieve your goals. Sports are also a feel-good activity because they help girls get in shape, keep a healthy weight, and make new friends.

5.　　 Playing sports can reduce stress and help you feel a little happier. How? The brain chemicals released during exercise improve a person's mood. Friends are another mood-lifter．And being on a team creates tight bonds between friends. It's good to know your teammates will support you－both on and off the field!

A. Exercise cuts the pressure.

B. Sports teach valuable life skills.

C. Regular exercise increases quality of life.

D. In fact, there are at least 5 more reasons.

E. Girls who play sports feel better about themselves.

F. Plying sports offers children more than just physical benefits.

G. But research shows that girls who play sports do better in school than those who don't.

高二英语信息匹配中等难度题查看答案及解析

Our team lost. We have tried our best and it was a good game, 　　 .

A.hence B.therefore C.then D.though

高二英语单项填空中等难度题查看答案及解析

Now Glen doesn’t like to think what might have happened had he and his best friends, Ray Wightman and Chris Johnson, picked their usual path along a rocky outcrop－the faster route to Johnson’s home on Triangle Mountain. They were heading there after school that day－April 14, 1999－to play street hockey in Johnson’s driveway. There were other lucky twists, too: not stopping at the shops to get a cola, as they usually did; hearing the strange cry.

It was 3:30 pm. The three teens were laughing and talking when suddenly they heard a strange cry coming from the ditch(沟渠) across the road. Crossing to take a look, they found an Adidas gym bag sitting deep in the icy water. They climbed down the steep bank and pulled the bag from the water, expecting to find abandoned cats or dogs inside. Instead, the boys found a trembling newborn girl. Wrapped in an old blanket, wearing a thin nightshirt, she was almost blue, her lips shaking from the cold and her crying.

The boys couldn’t have been more astonished. They knew this one needed to get warm and dry, although they didn’t know much about babies. Ray dug through his gym bag and wrapped her in a T-shirt. “We didn’t know what to do,” said Glen. “I didn’t think any of us had really held a baby before.” So the three stood beside the ditch, dumbfounded, taking turns to hold the baby to their chests to keep her warm.

“We knew it was no use walking up to Ray’s house, because his mum was working and no one would be home. We figured we’d have a better chance just staying by the road and flagging down someone.” So they stood there and waited.

A car drove by and the boys caught the driver’s attention, telling her that they had found a baby. The woman then drove off to get help. When the police and ambulance came 20 minutes later, the teens were told the baby was probably two or three hours old and had perhaps been in the ditch for an hour or more. They were also told that they had saved her life and that given 10-20 minutes more in the cold water, she probably would be drowned.

1.On April 14, 1999, Glen and his best friends ________.

A. were on their way to school

B. bought bottles of cola as usual

C. had intended to play street hockey

D. picked the faster route to Johnson’s home

2.When the three teens spotted an Adidas gym bag, ________.

A. they didn’t expect to find a baby

B. they found a cat crying in it

C. they found a little clog in it

D. they found the bag was wrapped in an old blanket

3.Why did the teens know it was no use walking up to Ray’s house?

A. Because it was too far away from Ray’s house.

B. Because his mum was working and no one would be home.

C. Because Ray’s parents had gone away on holiday elsewhere

D. Because the baby was in bad condition- and time was limited.

4.What can be the theme of the Text?

A. A life-changing twist　　 B. An icy ditch

C. Three warm-hearted teens　　 D. A lucky newborn girl

高二英语阅读理解中等难度题查看答案及解析

-----Why was our foreign teacher unhappy yesterday?

-----News about the hurricane(飓风) striking her country________an attack of homesickness.

A．set aside          B．set out            C．set off            D．set about

高二英语单项填空简单题查看答案及解析

－ I need to write an ad to rent out our place now.

－______? Michael is looking for a place.

A. Why not           B. What for         C. Why bother      D. So what

高二英语单项填空困难题查看答案及解析

——Why was our foreign teacher unhappy yesterday?

——News about the tsunami striking her country ____ an attack of homesickness.

A.set for　　　 B.set out　　　 C.set about　　 D.set off

高二英语单项填空简单题查看答案及解析

The telegram has faded out in our life now, and gone with____ are telegraph operators.

A. what           B. which         C. it               D. them

高二英语单项填空中等难度题查看答案及解析