题目内容
The scientists observed that the more junk food the rats ate, the more they wanted to eat – a behavior very similar to that of rats addicted(上了瘾的) to heroin, a dangerous drug. Johnson said the experiment shows that the brain chemistry of obesity(肥胖) and drug addiction may be quite similar.
In their experiment, Johnson and his team studied the “pleasure center” of rats’ brains. The pleasure center is a complicated network of nerve cells. If the animal exercises or eats, the cells reward the animal by releasing chemicals into the body that make it feel good. And when the body feels good, the animal – or person – will want to do the behavior again.
For the experiment, Johnson fed foods like cheesecake to one group of rats. Food like this is high in calories and fat. Another group of rats got a regular diet. The rats that ate junk food started to eat more and more.
“They’re taking in twice the amount of calories as the control rats,” says Paul Kenny, one of Johnson’s colleagues.
Kenny and Johnson wanted to know what was going on in the brains of these rats. They first designed a way to deliver a small electrical charge to the rats’ brains. This electrical charge would stimulate the pleasure centers to release pleasure-causing chemicals. The rats could control how much stimulation – and how much pleasure – they received by running on a wheel. The more the rat ran, the more pleasure it received.
The rats that had been eating junk food started running more and more. This behavior suggested that the junk-food-eating rats needed more brain stimulation to feel good compared with rats on a normal diet. In other words, their pleasure centers were becoming less sensitive and the junk food didn’t make them feel good unless they ate more and more.
Experiments like this one could help scientists understand how chemicals in the brain contribute to obesity. With that information, they may be able to help people avoid obesity in the first place.
(Note: Answer the questions or complete the statements in NO MORE THAN TEN WORDS.)
1.The scientists suggested it was actually ___________________ that made the rats feel good.
2.How did the scientist know what was happening in the brains of the junk-food-eating rats?
3.What was the purpose of the experiment mentioned in the article?
A．Means of e?waste recycling B．How e?waste comes into being C．The benefit of e?waste recycling D．The technologies of e?waste recycling E．The importance of the electronic waste recycle F．Modern technology brings convenience and e?waste |
1.
Modern technology does bring us many conveniences（便利），from Wi?Fi（无线网络）enabled cell phones and ever? smaller laptop computers that make entire lives easy to energy? efficient washers that use half the power and time to complete their tasks. However，these new toys and equipment finally become electronic waste （ 电子垃圾）（e? waste）once they are out of use.
2.
E? waste includes everything from empty printer ink containers to broken refrigerators. As people buy new items to replace aging electronics or make upgrades（升级），more electronic waste comes into being. In some cases，such as 2009's switch from analog（模拟）to digital television broadcasting in the United States，changes in technology are so great that old equipment may not even work at all with new systems.
3.
There are many reasons why it is important to recycle electronic waste. Much of the material used to construct electronics，including metal and plastic parts，can be recycled into new items at a discount of the cost and energy use needed to create things from new raw materials（原材料）. Additionally，many electronics contain poisonous substances （有毒物质）that are harmful to the environment and could be deadly if they go into an area's groundwater. When properly recycled，they can be reused and will not do harm to the environment. Because of these environmental concerns，many areas require by law that electronic waste be properly recycled.
4.
The availability（可用性）of e?waste recycling programs varies from place to place. In some areas，annual collections are held once or twice a year as a means of dealing with e?waste as well as used engine oil or other waste that is harmful to the environment. There are also some good alternatives （替代品） to recycling your e?waste. Any items that are in working condition can be given to friends or donated to charities（慈善机构）like Goodwill or the Salvation Army，who rely heavily on donations （ 捐赠） . Freecycling ，or passing on your unwanted items to those in need of them，is also a means of finding new homes for used items.
5.
E?waste recycling helps protect the environment by reducing the amount of poisonous materials placed in landfills（垃圾场）and saving recyclable parts to save energy and other resources. Recycling is a way of life. Stick to that choice every single day and recycling will become second nature to us.
Studying Abroad
Nowadays, studying abroad gains popularity in China. Many rich parents would rather send their children abroad to receive education than let them be educated in China.
As every coin has two sides, studying abroad is not an exception. There are advantages for people to attend schools abroad. In the first place, he can use the foreign language in his daily life so that his ability in the second language may be greatly improved, as it is obvious that there is no better chance to improve second language than living in the country where it is spoken. While studying in a foreign country, he will most likely meet many others from overseas and it is possible to make friends from all over the world. This is not only exciting on the social level, but could lead to important overseas contacts in his career as well. He can get familiar with the latest knowledge in science and make use of the first? rate facilities available. In this way, there is every chance that he is able to widen his horizon (眼界) and broaden his mind.
Of course, attending schools abroad may bring about a series of problems. The most serious problem is language barrier. Most of the students who go abroad don’t have enough skills in the language spoken there. As a result, on arriving there, they will find it difficult to understand what the teachers say. Besides, for lack of knowledge of the customs of the local people, they may constantly run into trouble in dealing with various situations.
Therefore, given an opportunity to attend a school abroad, one must consider both sides of the factors carefully before making up his mind.
Title: Studying Abroad
Phenomenon | Sending children abroad to receive education is 1. with many rich parents. |
Advantages | ● Children have the best 2. to improve the second language because they can use it 3.. ● They can make friends with other students from 4.． ● They can 5. the latest knowledge in science and have access to the best facilities. |
6. | ● Language barrier is the number one problem. Because students are not 7. at the language spoken there，they will have difficulty in 8. what the teachers say. ● It is not easy for them to deal with cross-cultural munication9.to lack of knowledge of the customs of the locals. |
Conclusion | Both sides of the factors should be 10. carefully before one makes a decision. |