We produce 500 billion of plastic bags in a year worldwide and they are thrown away polluting oceans, killing wildlife and getting dumped in landfills where they take up to 1000 years to decompose. Researchers have been unsuccessfully looking for a solution.
The 16-year old Canadian high school student, Daniel Burd, from Waterloo Collegiate Institute,
has discovered a way to make plastic bags degrade(分解) in as few as 3 months, a finding that won him first prize at the Canada－Wide Science Fair, a $10 000 prize, a $20 000 scholarship, and a chance to revolutionize a major environmental issue.
Burd's strategy was simple: Since plastic does eventually degrade, it must be eaten by microorganisms (微生物). If those microorganisms could be identified, we could put them to work eating the plastic much faster than under normal conditions.
With this goal in mind, he ground plastic bags into a powder and concocted(调制) a solution of household chemicals, yeast(酵母) and tap water to encourage microbes growth. Then he added the plastic powder and let the microbes work their magic for 3 months. Finally, he tested the resulting bacterial culture on plastic bags, exposing one plastic sample to dead bacteria as a control. Sure enough, the plastic exposed to the live bacteria was 17% lighter than the control after six weeks.
The inputs are cheap: maintaining the required temperature takes little energy because microbes produce heat as they work, and the only outputs are water and tiny levels of carbon dioxide.
“Almost every week I have to do chores and when I open the closet door, I have piles of plastic bags falling on top of me. One day, I got tired of it and I wanted to know what other people are doing with these plastic bags. The answer: not much. So I decided to do something myself.” said Daniel Burd.Daniel Burd won first prize at the Canada－Wide Science Fair because________.
| A．he found a new kind of microorganism |
| B．he contributed much to environmental protection |
| C．he found a way to degrade plastics in shorter time |
| D．he could encourage microbes growth in an easier way |
Daniel Burd exposed one plastic sample to dead bacteria to ________.
| A．make the live bacteria work better |
| B．test how effective his method was |
| C．know which bacteria worked faster |
| D．control the temperature in the process |
Maintaining the required temperature takes little energy because ________.
| A．plastics can get hot easily |
| B．microbes can produce heat themselves |
| C．much carbon dioxide is produced |
| D．the temperature can be controlled |
Daniel Burd got his idea from ________.
| A．his school textbook | B．the failure of researchers |
| C．his everyday work | D．the practice of other people |
What would life be like without rich, creamy, mouthwatering, melt-in-your-mouth chocolate?
Life would be bitter for most Americans. They spend about $13 billion a year buying all sorts of chocolate treats.
However, for the African children who toil under slavelike conditions on cacao plantations, life is not sweet. The cacao bean is the main ingredient in the chocolate. According to a 2002 survey by the International Institute of Tropical Agriculture and the US Agency for International Development, about 284,000 children work in dangerous conditions on cacao farms in western Africa.
More than half those children are younger than 14. Many were sold into forced labor to work 12 hours or more a day on the cacao plantations.
A number of international organizations, including several African governments, recently began a program to eliminate(消除) child labor on cacao plantations. Under the program, government officials will remove children from abusive working situations while teaching farmers about child labor issues.
The program will also make borrowing money easier for cacao farmers. Officials hope farmers will use the money to invest in their farms and hire paid laborers.The cacao bean is the main ingredient in _______.
| A．treats |
| B．coffee |
| C．chocolate |
| D．cigarettes |
How many children under 14 work on cacao farms in western Africa?
| A．About 284,000. |
| B．About 142,000. |
| C．About 467,000. |
| D．About 876,000. |
From the passage, you can reasonably conclude that _______.
| A．cacao farms in western Africa rely heavily on child labor |
| B．children in Africa know how to make the best chocolate |
| C．candy bars sold in the United States are made on plantations in Africa |
| D．eating too much chocolate is bad for your health |
Americans love dogs, all types of dogs: small dogs, big dogs, lapdogs (供玩赏的小狗). Each year, people spend billions of dollars on their four-legged pals, making sure the lovable dogs have enough food to eat and lots of toys to play with.
Dogs love people, too. They lick their faces, protect their homes. Where did these four-legged companions come from? Some scientists believe that they have found the answer.
Scientists have long known that dogs evolved from（演化） wolves. Exactly when the transformation from wolf to dog actually took place, however, remains a mystery.
Some said dogs evolved as a separate species 135,000 years ago in two parts of the world. One group of dogs developed in Europe and Asia from Asian wolves. The other group evolved in North, Central, and South America from American wolves.
Now researchers say those theories are wrong. New studies suggest that domesticated dogs first appeared 15,000 years ago in eastern Asia. Scientists also say that every modern dog descended from approximately five female Asian wolves, the mother of all modern dogs.
Scientists suspect dogs first set paws in North America by following settlers across a land bridge that once linked northern Asia and North America.According to recent studies, all modern dogs came from female wolves in ______.
| A．Asia | B．Africa |
| C．Europe | D．South America |
From this story, we can conclude that _______.
| A．dogs are scientists’ best friends |
| B．dogs are more like wolves than they are like any other animal |
| C．most dogs are from Africa |
| D．scientists have no idea how dogs evolved |
The underlined word “domesticated” means “_______”.
| A．tamed | B．indoor | C．intelligent | D．friendly |
The best title for this story might be ______.
| A．Why Cats Don’t Like Dogs |
| B．Barking up the Wrong Tree |
| C．Love Me, Love My Dog |
| D．Going from Wolf to Dog |
It’s a nightmare for Huazhong University of Science and Technology （HUST）: within a week，two students committed suicide by jumping off dorm buildings．对于整个华中科技大学来说，这简直就是场噩梦：一周之内，两名学生在宿舍跳楼自杀。
Officials from the university are reluctant to give interviews．校方官员们不愿接受采访。
“We had a hard time calming down students who were shocked at the suicides,” said Zhang Jingyuan，one official of HUST．
“Media coverage may arouse some students’ negative emotions again．Suicide can be contagious,” Zhang said．他说，“媒体的报道将会再次引发学生的消极情绪，自杀是会传染的。”
The university reacted promptly to the first suicide on October 23．对于今年10月23号发生的第一起自杀事件，华中科技大学迅速做出应急措施。
Advisors and class leaders conducted dorm-to-dorm checks to find students suffering depression．Then psychologists offered one-on-one counseling to them．辅导员和班长们走访了每个宿舍，找出遭遇抑郁的学生。然后，心理咨询师会为这些学生提供一对一的心理咨询。
Notice boards publicizing tips for identifying peers’ mental problems and offering help were set up in front of dorm buildings．Leaflets carrying similar information were handed out to each dorm．宿舍楼前竖起一些布告栏，为同学们普及关于如何发现身边人遭遇心理问题并提供帮助的小贴士。印有类似内容的小册子也被分发给每个寝室。
However，the second suicide came seven days later．然而，七天后，第二起自杀事件发生了。
Both students were described as men of few words．Their schoolmates didn’t see anything to indicate suicide．据周围人描述，这两名学生都很少言寡语。他们的同学都没有觉察到任何自杀前的征兆。
Zhang revealed that the two students had been bothered by mental disorders．But the school didn’t know this until the students’ close friends outside school and their parents unveiled the truth after the suicides．章劲元透露，这两名学生曾经饱受心理疾病的困扰。但是学校对此并不知情，他们校外的好友和家长也是在自杀事件发生后才说出实情。
According to Zhang，there are only three full-time counselors working in the university’s counseling center for its 60,000 students．He complained: “It’s unrealistic to rely only on counselors to detect students’ mental problems．”据章劲元说，全校共有六万名学生，但学校的心理咨询中心只有三位全职心理咨询师。他抱怨说：“仅仅依靠心理咨询师来察觉学生的心理问题，这是不现实的。”
Effective prevention comes from long-term education for life instead of temporary intervention to meet an emergency，said Hu Yi’an．Hu delivers a course of lectures on life and death at Guangzhou University．He worries that universities have paid little attention to education for life．有效的预防来自于长期的生命教育，而并非遭遇紧急状况时的临时干预，胡毅安（音译）说。他在广州大学教授以生命和死亡为主题的课程。他为各大高校给予生命教育的关注少之又少而担忧。
“Education for life helps students respect and love life so they won’t resort to ending their lives when they have difficulties,” said Hu．“生命教育可以帮助学生尊重、热爱生命，这样一来，当他们遇到困难的时候就不会选择结束生命了,” 胡毅安说。
According to Hu，the principles can be incorporated into everyday teaching．胡毅安还表示，这些观念可以融入到日常教学中去。
Hu is also concerned that some universities are conveying discriminatory message that will hold back students from seeking help．胡老师也很担心一些大学传递出带有歧视性的信息会使得学生们不愿去寻求帮助。
When HUST conducted the dorm-to-dorm examination，students with poor academic performance were paid special attention．In March，Peking University also released a controversial policy，which required teachers to have a chat with students “with biased thinking”．当华中科技大学校方挨个宿舍进行走访时，学习成绩较差的学生也被给予了特别关照。三月份，北京大学也推行了一项备受争议的政策，该新规要求教师们要找那些学生中的“激进分子”谈话。
However，Hu suggested that students step out of their comfort zone to seek real-life communication．The underlined word “reluctant” in paragraph 2 probably means “”．
| A．willing | B．unhappy | C．refused | D．decided |
Which measure the university took to the first suicide is incorrect?
| A．Conducting checks to find out the students’ depression． |
| B．Offering counseling to the students． |
| C．Setting up notice boards publicizing tips for identifying peers’ mental problems and offering help． |
| D．Handing out leaflets to each student． |
Which of the following is right according to the text?
| A．Officials of HUST were willing to give the details about the suicide． |
| B．HUST didn’t respond to the first suicide． |
| C．What the university about the suicide was a success． |
| D．Their close friends and parents did know the students had mental disorder． |
What’s the main idea of the passage?
| A．Two students of HUST committed suicide． |
| B．What can we do to prevent the student’s suicide? |
| C．The reasons why the students committed suicide． |
| D．The dangers in the universities in China． |
Imagine that the genome （基因组） is a book．The book consists of 23 chapters with thousands of stories made up of paragraphs, words and letters on different levels．There are one billion words in the book, as long as 800 Bibles; if I read the genome out to you at the rate of one word per second for eight hours a day, it would take me centuries; if I wrote out the human genome, one letter per millimeter, my text would be as long as the River Danube．This is a huge volume, a book of great length, but it all fits inside an extremely small cell nuclear（细胞核） that fits easily upon the head of a pin．
The idea of the genome as a book is not, strictly speaking, even a metaphor．It is true to a great extent．A book is a piece of digital information, written in one-directional form and defined by a code that translates a small alphabet of signs into a large dictionary of meanings through the order of their groupings．So is a genome．The only difference is that all English books read from left to right, while some parts of the genome read from left to right while some from right to left, but never both at the same time．
While English books are written in words of different lengthens using twenty-six letters, genomes are written entirely in words of three-letter length, using only four letters, and instead of being written on flat pages, they are written on long chains of DNA molecules （分子）．
The genome is a very clever book, because in the right condition it can both photocopy itself and read itself．How do human genomes read according to the passage?___________
| A．Only from left to right． |
| B．Only from right to left． |
| C．From both directions at the same time． |
| D．From one direction at a time． |
We can learn from the passage that the human genome ________．
| A．is as long as the River Danube |
| B．can be easily placed on the head of a pin |
| C．is coded with an alphabet of four letters |
| D．is smart enough to read and take photos of itself |
It can be concluded that the passage is mainly written for ______．
| A．specialists in the field |
| B．general readers |
| C．natural scientists |
| D．readers with professional knowledge |
The real purpose of the author’s comparison of the genome to a book is _____．
| A．to focus on the differences between the two |
| B．to lay emphasis on the similarities between the two |
| C．to simplify the concept of the human genome |
| D．to give an exact description of the human genome |
It is reported that conservation groups in North America have been arguing about the benefits and dangers of wolves. Some groups believe wolves should be killed. Other people believe wolves must be protected so that they will not disappear from the wilderness (荒野)
For Killing Wolves
In Alaska, the wolf almost disappeared a few years ago, because hunters were killing hundreds of them for sport. However, 1aws were established to protect the wolves from sportsmen and people who catch the animals for their fur. So the wolf population has greatly increased. Now there are so many wolves that they are destroying their own food supply.
A wolf naturally eats animals in the deer family. People in the wilderness also hunt deer for food. Many of the animals have been destroyed by the very cold winters recently and by changes in the wilderness plant life. When the deer can’t find enough food, they die.
If the wolves continue to kill large numbers of deer, their prey (猎物) will disappear some day. And the wolves will, too. So we must change the cycle of life in the wilderness to balance the ecology(生态平衡）. If we killed more wolves, we would save them and their prey from dying out. We’d also save some farm animals.
In another northern state, wolves attack cows and chickens for food. Farmers want the government to send biologists to study the problem. They believe it necessary to kill wolves in some areas and to protect them in places where there is a small wolf population.
Against Killing Wolves
If you had lived long ago, you would have heard many different stories about the dangerous wolf. According to most stories, hungry wolves often kill people for food. Even today, the stories of the “big bad wolf'” will not disappear.
But the fact is wolves are afraid of people, and they seldom travel in areas where there is a human smell. When wolves eat other animals, they usually kill the very young, or the sick and injured .The strongest survive .No kind of animal would have survived through the centuries if the weak members had lived. And has always been a law of nature.
Although some people say it is good sense to kill wolves, we say it is nonsense! Researchers have found wolves and their prey living in balance. The wolves keep the deer population from becoming too large, and that keeps a balance in the wilderness plant life.
The real problem is that the areas where wolves can live are being used by people. Even if wilderness land is not used directly for human needs, the wolves can’t always find enough food. So they travel to the nearest source, which is often a farm. Then there is danger. The“big bad wolf”has arrived! And everyone knows what happens next.Some people are against killing wolves because ________.
| A．there are too many deer in the wilderness |
| B．wolves are afraid of people and never attack people |
| C．wolves help to keep the ecological balance in the wilderness |
| D．there is too small a wolf population in the wilderness |
According to those against killing wolves, when wolves eat other animals, ________.
| A．they might help this kind of animals survive in nature |
| B．they disturb the ecological balance in the wilderness |
| C．they never eat strong and healthy ones |
| D．they always go against the law of nature |
The last sentence “And everyone knows what happens next” implies that in such cases _______.
| A．wolves will find enough food sources on farms |
| B．people will leave the areas where wolves can live |
| C．farm animals will be in danger and have to be shipped away |
| D．wolves will kill people and people will in turn kill them |