A black hole is a place in space where gravity pulls so much that even light cannot get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying.
Because no light can get out, people can’t see black holes. Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently from other ones.
Black holes can be big or small. Scientists think the smallest black holes are as small as just one atom. These black holes are very tiny but have the mass of a large mountain. Mass is the amount of matter, or “staff”, in an object.
Another kind of black hole is called “stellar”(星球黑洞). Its mass can be up to 20 times more than the mass of the sun. There may be many stellar mass black holes in Earth’s galaxy. Earth’s galaxy is called the Milky Way.
The largest black holes are called “supermassive”(超大质量黑洞). These black holes have masses that are more than one million suns together. Scientists have found proof that every large galaxy contains a supermassive black hole at its center. The supermassive black hole at the center of the Milky Way galaxy has a mass equal to about four million suns and would fit inside a very large ball that could hold a few million Earths.
Scientists think the smallest black holes formed when the universe began. Stellar black holes are made when the center of a very big star falls in upon itself, or falls apart. When this happens, it exploded part of the star into space. Scientists think supermassive black holes were made at the same time as the galaxy they are in.
A black hole can not be seen because strong gravity pulls all of the light into the middle of the black hole. But scientists can see how the strong gravity affects the stars and gas around the black hole. Scientists can study stars to find out if they are flying around, or orbiting a black hole.
When a black hole and a star are close together, high-energy light is made. This kind of light cannot be seen with human eyes. Scientists use satellites and telescopes in space to see the high-energy light. The gravity of a black hole may become so strong that light cannot get out when ____________.
| A．the star is going to die |
| B．special tools are used on it |
| C．other stars come close to it |
| D．it is seen from the space telescopes |
According to the passage, which of the following is NOT true?
| A．A black hole can be very tiny but extremely heavy. |
| B．The gravity of a black hole holds all light in its center. |
| C．Scientists observe high-energy light through their own eyes. |
| D．Some small black holes came into being as early as the universe. |
Which can be inferred from the passage?
| A．Every galaxy must have a black hole. |
| B．A galaxy is the center of the universe. |
| C．A galaxy consists of a large group of stars and planets. |
| D．Earth’s galaxy is called the Milky Way. |
What does the last sentence in Paragraph 5 suggest?
| A．Neither the sun nor the earth is as heavy as a black hole. |
| B．There is only one supermassive black hole at the center of the Milky Way. |
| C．The supermassive black hole had existed before the Milky Way was formed. |
| D．There is a reason why the large black holes are called “supermassive”. |
The last two paragraph mainly focus on the question of _________.
| A．what a black hole is |
| B．how black holes form |
| C．how big black holes are |
| D．how scientists know about black holes |
Good Housekeeping has discovered that even if a child wear a helmet when she bikes, or skates, it may not protect her from a serious head injury.
Every year, 390,000 children under age 15 go to hospital emergency rooms with bike-related injuries. Of that number, about one third children suffer head injuries and an estimated 200 die. By wearing a helmet, a child can reduce her risk of injury by as much as 85 percent. But remember —— a bicycle helmet must fit properly to be safe. Here are five steps to making sure your child's helmet fits properly.
1) If you haven't bought your child's helmet already, you might want to consider one with a rear stabilizer(稳定杆). A rear stabilizer holds the back of the head gently and helps the helmet stay correctly positioned.
2) The helmet should fit closely and shouldn't slide from side to side or front to back. If your child can put two fingers on both temples inside the helmet, it's too big. Try a smaller size. But if the next size down is too small, use the fit pads(护垫). Fit pads come in different sizes and attach to the helmet with Velcro.
3) Tell your child to open her mouth widely and ask if she can feel the helmet push down onto the top of her head. If she can't, you need to readjust her helmet.
4) To prevent strap slippage, wind a rubber band around the strap where it meets the fastener.
5) Recheck the fit regularly.
You should replace the bicycle helmet:
If she has been in an accident with it.
If the buckle(金属扣) breaks or if a piece breaks off.
If it doesn't have a U.S. Consumer Product Safety Commission, American Society for Testing and Materials, or Snell Memorial Foundation sticker.
If it doesn't fit correctly. Even if the helmet fit perfectly two years ago, it might be too small now.Who is this passage mainly written for?
| A．Children. | B．Teachers. | C．Parents. | D．helmet producers. |
What does the author mainly want to stress in the second paragraph?
| A．The bike-related injury is a serious threat to the children. |
| B．The bicycle helmets must fit properly while the children are biking. |
| C．It’s necessary for the children to wear helmets while biking. |
| D．Many students suffer bike-related injuries every year. |
If a girl finds a helmet a little bit big for her head, what should she do?
| A．She must buy a smaller size. |
| B．She can use some fit pads. |
| C．She can put fingers on both temples inside the helmet. |
| D．She must make helmet slide from side to side. |
Phil White, a father, found the buckle of his girl’s helmet broken, he can_______
| A．buy a new bicycle helmet for her |
| B．mend the bicycle helmet himself |
| C．continue to use the bicycle helmet |
| D．throw away the broken buckle |
Ethiopia has greatly reduced its death rates for children under the age of five years during the last two decades, new UN statistics show. The report says Ethiopia has cut the number of child deaths, by two thirds or so, to 68 per 1,000 births compared to that in 1990.
The government owed the improved figures to its growing economy. Despite the reduction, the UN Children's Fund said Ethiopia needed to do much more to improve health facilities(设施) for pregnant women.
Ethiopia is one of Africa's poorest states, although it has experienced rapid economic growth in recent years and is one of the continent's leading coffee producers. Its economy centers around agriculture, which in turn relies on rainfall.
The BBC's Emmanuel Igunza in the capital, Addis Ababa, says Ethiopia was once representative of poor nutrition in Africa. But the latest UNICEF(联合国儿童基金会) figures show Ethiopia is one of the few African countries on the path to realizing the development goal of reducing child death rates, he says.
Ethiopia's Health Minister Kesetebirhan Admasu said increasing family incomes had helped improve people's health. "This has also resulted in better nutrition for children and women; this has translated into better medical conditions —— all these have a direct or indirect influence on the survival of children," he told BBC Africa. He said the government has also been "aggressively expanding its primary health care network".
"We have now 93% coverage(覆盖) of one health centre for 25,000 people, which basically means one health facility within a 7km area," he said.How many in 1000 births would die in Ethiopia in 1990?
| A．about 680 | B．about 330 | C．about 68 | D．about 200 |
Which of the following statements is true?
| A．Ethiopian children benefit from its fastest economy growing. |
| B．Ethiopia has a long way to go to improve health facilities. |
| C．Ethiopia is the economic center because of its rich rainfall. |
| D．Ethiopia has already become a rich state in Africa. |
What do we know according to the latest UNICEF figures?
| A．Many African countries have high child death rates now. |
| B．Ethiopia is the only country that has reduced child death rates. |
| C．Ethiopia is the most successful in reducing child death rates. |
| D．Ethiopia was once known for its poor nutrition in Africa. |
What Kesetebirhan Admasu said shows that_______.
| A．agricultural incomes have helped improve all the people's health in Africa |
| B．now the health care network is perfect in Ethiopia |
| C．93% of the 25,000 people enjoy health centers in Ethiopia |
| D．the government has been taking active measures to improve people's health |
This parable（寓言）is told of a farmer who owned an old mule（骡子）. The mule fell into the farmer’s well. The farmer heard the mule praying for whatever mules do when they fall into wells. After carefully assessing（评估）the situation, the farmer sympathized（同情）with the mule, but decided that neither the mule nor the well was worth the trouble of saving. Instead, he called his neighbors together , told them what had happened, and asked them to help pour dirt to bury the old mule in the well and put him out his misery.
At the beginning, the old mule was crazy! But as the farmer and his neighbors continued shovelling and the dirt hit his back, a thought struck him. It suddenly dawned on him that every time a shovel load of dirt landed on his back, he would shake it off and step up!
This he did, blow after blow. “Shake it off and step up… shake it off and step up… shake it off and step up!” He repeated to encourage himself. No matter how painful the blows, or how distressing the situation seemed, the old mule fought panic and just kept right on shaking it off and stepping up!
It wasn’t long before the old mule, battered and exhausted, stepped triumphantly（胜利地）over the wall of that well! What seemed like it would bury him actually helped him… all because of the manner in which he handled his adversity（逆境）.
That’s life! If we face our problems and respond to them positively, and refuse to give in to panic, bitterness, or self-pity.
The adversities that come along to bury us usually have within them the very real potential to benefit us! Never be afraid to try something new. Remember that amateurs（生手）built the boat. Professionals built the Titanic.Why did the farmer decide to bury the mule in the well?
| A．Because he thought the mule was of little use. |
| B．Because he didn’t like the praying made by the mule. |
| C．Because he thought the well couldn’t be used any longer after the accident. |
| D．Because he didn’t want to see the mule suffer more in the well. |
What does the underlined sentence in the second paragraph mean?
| A．The mule became calm | B．The mule became quiet. |
| C．The mule suddenly had an idea | D．The mule lost heart. |
Who saved the mule at last?
| A．The farmer | B．The farmer’s neighbors |
| C．The farmer and his neighbors | D．The mule himself |
What lesson can we learn from the passage?
a. One should give up something of little use.
b. One should depend oneself when in trouble.
c. One should show mercy to others who are in trouble.
d. There must be something that one can do well no matter what he is.
e. Be self-determined and never give up, and one can succeed in the end.
| A．a, b, e | B．b, d, e | C．a, c, e | D．b, c, e |
Most of us know little about the mental processes that lie behind our decisions. Luckily, what psychologists are finding may help us all make better choices. Here are some of their amazing discoveries to help you make up your mind.
Consider your emotions. You might think that emotions are the enemy of decision making, but in fact they’re a part of it. Whenever you make up your mind, your brain’s emotional center is active. University of Southern California scientist, Antonio Damasio, has studied people with damage to only the emotional parts of their brains, and found that they were unable to make basic choices about what to wear or eat. Damasio thinks this may be because our brains store emotional memories of past choices, which we use to help the present decision making.
However, making choices under the influence of an emotion can greatly affect the result. Take anger, for example. A study by Nitika Garg of the University of Mississippi and other scientists found the angry shoppers were more likely to choose the first thing they were offered rather than considering other choices. It seems anger can lead us to make quick decisions without much thinking.
All emotions affect our thinking and motivation, so it may be best to avoid making important decisions under their influence. Yet strangely there’s one emotion that seems to help us make good choices. The American researchers found that sad people took time to consider the various choices on offer, and ended up making the best choices. In fact many studies show that people who feel unhappy have the most reasonable view of the world.According to the text, what may help us make better decisions?
| A．To think about happy times. |
| B．To make many decisions at a time. |
| C．To stop feeling regretful about the past. |
| D．To learn about the process of decision-making. |
Damasio’s study suggests that ______.
| A．emotions are the enemy of decision making |
| B．our brain has nothing to do with decision making |
| C．people with physical damage find it hard to make up their minds |
| D．our emotional memories of past choices can affect present decisions |
Why are angry shoppers more likely to choose the first thing they are offered?
| A．They often forget their past choices. |
| B．They make decisions without much thinking. |
| C．They tend to save time when shopping. |
| D．They are too angry to bargain. |
What do we learn from the text?
| A．Emotions are a part of decision making. |
| B．Sad people always make the worst choices. |
| C．No emotion seems to help us make good choices. |
| D．Only sad feelings affect our thinking and motivation. |
I was appreciating my family photos on my computer, admiring my two beautiful babies, when I found a disturbing trend: my laptop was in almost all the pictures. There was my daughter, 8 months old, playing at my feet while I was typing away on the couch. There was me and my son, with the laptop at my side as I held him in my arms.
I’d heard about the Internet addiction before, but always assumed I was something limited to socially challenged guys who played too much World of Warcraft (a computer game). Now it seemed my Internet “habit” is slowly but surely crossing the line. Sometimes I find myself up at midnight, surfing the Web while my family are sleeping. I read news, keep up with friends and write my blog … just for something to do.
It turns out that I’m not the only mama who is addicted to the computer. These moms are contributing to a growing global addiction. There’s a movement among psychiatrists (doctors who specialize in mental diseases) to recognize the Internet addiction as an official mental disorder. And a recent Stanford University national survey found that 14 percent of Internet users find it hard to stay away from it for several days at a time; 9 percent try to hide their “unnecessary Internet use” from their loved ones; 8 percent admit they use the Web as a way to escape problems.
You’re likely not the kind of addict who doesn’t bathe and abuses drugs to help her stay “up” for more online time. You may have noticed, though, that going online has become a necessary part of your life, which, at least, means a load of clothes go unwashed.
It may also mean you’re missing much time with you baby – something you probably do care about.From Paragraph 1, we can conclude that _______.
| A．the author was busy taking care of her babies |
| B．the author’s job had something to do with computers |
| C．the author was not good at taking photos of her babies |
| D．the author looked after her babies while using the computer. |
The author used to think that the Internet addiction is ________.
| A．using the web at midnight | B．keeping up with friends online |
| C．spending too much time online | D．being addicted to computer games |
In medical terms, the Internet addiction is ________.
| A．a personal life habit | B．a way to escape problems |
| C．an official mental disorder | D．the unnecessary use of the Internet |
What does the author want to express in the last but one paragraph?
| A．Many women still can control their online time. |
| B．The Internet addiction influences housewives’ lives a lot. |
| C．Going online has become a necessary part of women’s lives. |
| D．Many people don’t realize that they are addicted to the Internet. |