Plastic-Eating Worms
Humans produce more than 300 million tons of plastic every year. Almost half of that winds up in landfills(垃圾填埋场), and up to 12 million tons pollute the oceans. So far there is no effective way to get rid of it, but a new study suggests an answer may lie in the stomachs of some hungry worms.
Researchers in Spain and England recently found that the worms of the greater wax moth can break down polyethylene, which accounts for 40% of plastics. The team left 100 wax worms on a commercial polyethylene shopping bag for 12 hours, and the worms consumed and broke down about 92 milligrams, or almost 3% of it. To confirm that the worms' chewing alone was not responsible for the polyethylene breakdown, the researchers made some worms into paste(糊状物) and applied it to plastic films. 14 hours later the films had lost 13% of their mass - apparently broken down by enzymes (酶) from the worms' stomachs. Their findings were published in Current Biologyin 2017.
Federica Bertocchini, co-author of the study, says the worms' ability to break down their everyday food - beeswax - also allows them to break down plastic. ＂Wax is a complex mixture, but the basic bond in polyethylene, the carbon-carbon bond, is there as well, ＂she explains, ＂The wax worm evolved a method or system to break this bond. ＂
Jennifer DeBruyn, a microbiologist at the University of Tennessee, who was not involved in the study, says it is not surprising that such worms can break down polyethylene. But compared with previous studies, she finds the speed of breaking down in this one exciting. The next step, DeBruyn says, will be to identify the cause of the breakdown. Is it an enzyme produced by the worm itself or by its gut microbes(肠道微生物)?
Bertocchini agrees and hopes her team's findings might one day help employ the enzyme to break down plastics in landfills. But she expects using the chemical in some kind of industrial process - not simply ＂millions of worms thrown on top of the plastic.＂
（1）What can we learn about the worms in the study?
| A． |
They take plastics as their everyday food. |
| B． |
They are newly evolved creatures. |
| C． |
They can consume plastics. |
| D． |
They wind up in landfills. |
（2）According to Jennifer DeBruyn, the next step of the study is to .
| A． |
identify other means of the breakdown |
| B． |
find out the source of the enzyme |
| C． |
confirm the research findings |
| D． |
increase the breakdown speed |
（3）It can be inferred from the last paragraph that the chemical might .
| A． |
help to raise worms |
| B． |
help make plastic bags |
| C． |
be used to clean the oceans |
| D． |
be produced in factories in future |
（4）What is the main purpose of the passage?
| A． |
To explain a study method on worms. |
| B． |
To introduce the diet of a special worm. |
| C． |
To present a way to break down plastics. |
| D． |
To propose new means to keep eco-balance. |
Antarctica and Environment
Antarctica has actually become a kind of space station – a unique observation post for detecting important changes in the world’s environment. Remote from major sources of pollution and the complex geological and ecological systems that prevail elsewhere, Antarctica makes possible scientific measurements that are often sharper and easier to interpret than those made in other parts of the world.
Growing numbers of scientists therefore see Antarctica as a distant-early-warning sensor, where potentially dangerous global trends may be spotted before they show up to the north. One promising field of investigation is glaciology. Scholars from the United States, Switzerland, and France are pursuing seven separate but related projects that reflect their concern for the health of the West Antarctic Ice Sheet – a concern they believe the world at large should share.
The Transantarctic Mountain, some of them more than 14,000 feet high, divide the continent into two very different regions. The part of the continent to the “east” of the mountains is a high plateau covered by an ice sheet nearly two miles thick. “West” of the mountain, the half of the continent south of the Americas is also covered by an ice sheet, but there the ice rests on rock that is mostly well below sea level. If the West Antarctic Ice Sheet disappeared, the western part of the continent would be reduced to a sparse cluster of island.
While ice and snow are obviously central to many environmental experiments, others focus on the mysterious “dry valley” of Antarctica, valleys that contain little ice or snow even in the depths of winter. Slashed through the mountains of southern Victoria Land, these valleys once held enormous glaciers that descended 9,000 feet from the polar plateau to the Ross Sea. Now the glaciers are gone, perhaps a casualty of the global warming trend during the 10,000 years since the ice age. Even the snow that falls in the dry valleys is blasted out by vicious winds that roars down from the polar plateau to the sea. Left bare are spectacular gorges, rippled fields of sand dunes, clusters of boulders sculptured into fantastic shapes by 100-mile-an-hour winds, and an aura of extraterrestrial desolation.
Despite the unearthly aspect of the dry valleys, some scientists believe they may carry a message of hope of the verdant parts of the earth. Some scientists believe that in some cases the dry valleys may soak up pollutants faster than pollutants enter them.What is the best title for this passage?
A Antarctica and environmental Problems.
B Antarctica: Earth’s Early-Warning station.
C Antarctica: a Unique Observation Post.
D Antarctica: a Mysterious Place.What would the result be if the West Antarctic Ice Sheet disappeared?
A The western part of the continent would be disappeared.
B The western part of the continent would be reduced.
C The western part of the continent would become scattered Islands.
D The western part of the continent would be reduced to a cluster of Islands.Why are the Dry Valleys left bare?
A Vicious wind blasts the snow away. B It rarely snows.
C Because of the global warming trend and fierce wind. D Sand dunes.Which of the following is true?
A The “Dry Valleys” have nothing left inside.
B The “Dry Valleys” never held glaciers.
C The “Dry Valleys” may carry a message of hope for the verdant.
D The “Dry Valleys” are useless to scientists.
The physicians in a hospital form the center of medical staff. But they could not provide effective medical care to their patients without the help of numerous other medical employees. From the viewpoint of the patients, the nursing staff is particularly important. Nurses are usually in close contact with patients as long as they are in the hospital.
A nurse does not study for as many years as a doctor. however, each must be equally dedicated. Caring for sick persons requires a great deal of patience and concern. Most nurses work long days, and they often must work at odd hours or during the night.
Under the supervision (监管) of the head nurse, the nursing staff must provide nursing services on a 24-hour basis and attend to patients’ needs. This responsibility continues around the clock, and so nurses must work in shifts. A shift is a period of duty, usually eight in length. The nurses on the ward rotate their shifts. Some take turns working night duty; others work odd shifts.
A nurse must always be alert. She can never afford to be careless. This is true in all nursing situation, but it is especially true in the intensive care unit. Patients under intensive care are critically ill, and they must be monitored at all times. The nurses who do intensive care duty have one of the most demanding jobs in the hospital.
Serving as a nurse can be a very rewarding job. But it is not an easy one. Not every person is suited to become a nurse. Only very dedicated people have chosen nursing as a profession.The nursing staff ________.
| A．are central to the medical staff |
| B．play an important role in caring for patients |
| C．can work effectively without physicians |
| D．are always in close contact with the patients |
Why don’t nurses study for as many years as doctors?
| A．They don’t treat patients for illness and injury. |
| B．Most nurses work long days. |
| C．Caring for sick patients requires patience and concern. |
| D．They are not dedicated. |
Nurses work in shifts because ________.
| A．they are careless. |
| B．nursing services must be provided continuously. |
| C．they work at night from time to time. |
| D．a shift is usually eight hours long. |
What kind of person is suited to become a nurse?
| A．A very careful person. | B．An able person. |
| C．A very dedicated person. | D．A specially trained person. |
The Neutrality of American in the Early World War II
The establishment of the Third Reich influenced events in American history by starting a chain of events which culminated in war between Germany and the United States. The compete destruction of democracy, the persecution of Jews, the war on religion, the cruelty and barbarism of the Nazis, and especially the plans of Germany and her allies, Italy and Japan, for world conquest caused great indignation in this country and brought on fear of another world war. While speaking out against Hitler’s atrocities, the American people generally favored isolationist policies and neutrality. The Neutrality Acts of 1935 and 1936 prohibited trade with any belligerents or loans to them. In 1937 the President was empowered to declare an arms embargo in wars between nations at his discretion.
American opinion began to change somewhat after President Roosevelt’s “quarantine the aggressor” speech at Chicago (1937) in which he severely criticized Hitler’s policies. Germany’s seizure of Austria and the Munich Pact for the partition of Czechoslovakia (1938) also aroused the American people. The conquest of Czechoslovakia in March, 1939 was another rude awakening to the menace of the Third Reich. In August, 1939 came the shock of the Nazi-soviet Pact and in September the attack on Poland and the outbreak of European war. The United States attempted to maintain neutrality in spite of sympathy for the democracies arrayed against the Third Reich. The Neutrality Act of 1939 repealed the arms embargo and permitted “cash and carry” exports of arms to belligerent nations. A strong national defense program was begun. A draft act was passed (1940) to strengthen the military services. A Lend Act (1941) authorized the President to sell, exchange, or lend materials to any country deemed necessary by him for the defense of the United States. Help was given to Britain by exchanging certain overage destroyers for the right to establish American bases in British territory in the Western Hemisphere. In August, 1940 President Roosevelt and Prime Minister Churchill met and issued the Atlantic Charter which proclaimed the kind of a world which should be established after the war. In December, 1941, Japan launched the unprovoked attack on the United States at Pearl Harbor. Immediately thereafter, Germany declared war on the United States.One item occurring before 1937 that the author does not mention in his list of actions that alienated the American public was
A the burning of the Reichstag. B German plans for conquest.
C Nazi barbarism. D the persecution of religious groups.The Lend-Lease Act was designed to
A help the British.
B strengthen the national defense of the United States.
C promote the Atlantic Charter.
D avenge Pearl Harbor.American Policy during the years 1935-1936 may be described as being
A watchful. B isolationist. C peaceful. D indifferent.The Neutrality Act of 1939
A permitted the selling of arms to belligerent nations.
B antagonized Japan.
C permitted the British to trade only with the Allies.
D led to Lend-Lease Act.We entered the war against Germany
A because Germany declared war.
B because Japan was an ally of Germany.
C after Germany had signed the Nazi-soviet Pact.
D after peaceful efforts had failed.
We Should All Grow Fat and Be Happy
Here’s a familiar version of the boy-meets-girl situation. A young man has at last plucked up courage to invite a dazzling young lady out to dinner. She has accepted his invitation and he is overjoyed. He is determined to take her to the best restaurant in town, even if it means that he will have to live on memories and hopes during the month to come. When they get to the restaurant, he discovers that this ethereal creature is on a diet. She mustn’t eat this and she mustn’t that. Oh, but of course, she doesn’t want to spoil his enjoyment. Let him by all means eat as much fattening food as he wants: it’s the surest way to an early grave. They spend a truly memorable evening together and never see each other again.
What a miserable lot dieters are! You can always recognize them from the sour expression on their faces. They spend most of their time turning their noses up at food. They are forever consulting calorie charts; gazing at themselves in mirrors; and leaping on to weighing-machines in the bathroom. They spend a lifetime fighting a losing battle against spreading hips, protruding tummies and double chins. Some wage all-out war on FAT. Mere dieting is not enough. They exhaust themselves doing exercises, sweating in sauna baths, being pummeled and massaged by weird machines. The really wealthy diet-mongers pay vast sums for ‘health cures’. For two weeks they can enter a nature clinic and be starved to death for a hundred guineas a week. Don’t think it’s only the middle-aged who go in for these fads either. Many of these bright young things you see are suffering from chronic malnutrition: they are living on nothing but air, water and the goodwill of God.
Dieters undertake to starve themselves of their own free will; so why are they so miserable? Well, for one thing, they’re always hungry. You can’t be hungry and happy at the same time. All the horrible concoctions they eat instead of food leave them permanently dissatisfied. Wonderfood(奇妙的事物) is a complete food, the advertisement says. ‘Just dissolve a teaspoonful in water…’. A complete food it may be, but not quite as complete as a juicy steak. And, of course, they’re always miserable because they feel so guilty. Hunger just proves too much for them and in the end they lash out and devour five huge guilt-inducing cream cakes at a sitting. And who can blame them? At least three times a day they are exposed to temptation. What utter torture it is always watching others tucking into piles of mouth-watering food while you munch a water biscuit and sip unsweetened lemon juice!
What’s all this self-inflicted torture for? Saintly people deprive themselves of food to attain a state of grace. Unsaintly（saintly<圣洁的>的反义词） people do so to attain a state of misery. It will be a great day when all the dieters in the world abandon their slimming courses; when they hold out their plates and demand second helpings!The best title for this passage is
A On Fat.
B We Should All Grow Fat and Be Happy.
C Many Diseases Are Connected with Fat.
D Diet Deprives People of Normal Life. Why do they never see each other again?
A Because it is a memorable evening.
B Because she lets him eat as much fattening food as he wants.
C Because she does not eat this and drink that.
D Because eating fattening food is the surest way to an early grave.Which of the following ways is NOT mentioned for diet?
A Doing exercises. B Not eating sugar. C Not eating fat. D Taking sauna baths.What is the author’s attitude toward diet?
A Persuasive. B Critical. C Indifferent. D Adversative.
Antinuclear Demonstration
Police fired tear gas and arrested more than 5,000 passively resisting protestors Friday in an attempt to break up the largest antinuclear demonstration ever staged in the United States. More than 135,000 demonstrators confronted police on the construction site of a 1,000-megawatt nuclear power plant scheduled to provide power to most of southern New Hampshire. Organizers of the huge demonstration said, the protest was continuing despite the police actions. More demonstrators were arriving to keep up the pressure on state authorities to cancel the project. The demonstrator had charged that the project was unsafe in the densely populated area, would create thermal pollution in the bay, and had no acceptable means for disposing of its radioactive wasters. The demonstrations would go on until the jails and the courts were so overloaded that the state judicial system would collapse.
Governor Stanforth Thumper insisted that there would be no reconsideration of the power project and no delay in its construction set for completion in three years. “This project will begin on time and the people of this state will begin to receive its benefits on schedule. Those who break the law in misguided attempts to sabotage the project will be dealt with according to the law,” he said. And police called in reinforcements from all over the state to handle the disturbances.
The protests began before dawn Friday when several thousand demonstrators broke through police lines around the cordoned-off construction site. They carried placards that read “No Nukes is Good Nukes,” “Sun-power, Not Nuclear Power,” and “Stop Private Profits from Public Peril.” They defied police order to move from the area. Tear gas canisters fired by police failed to dislodge the protestors who had come prepared with their own gas masks or facecloths. Finally gas-masked and helmeted police charged into the crowd to drag off the demonstrators one by one. The protestors did not resist police, but refused to walk away under their own power. Those arrested would be charged with unlawful assembly, trespassing, and disturbing the peace.What were the demonstrators protesting about?
A Private profits. B Nuclear Power Station.
C The project of nuclear power construction. D Public peril.Who had gas-masks?
A Everybody. B A part of the protestors.
C Policemen. D Both B and C.Which of the following was NOT mentioned as a reason for the demonstration?
A Public transportation. B Public peril.
C Pollution. D Disposal of wastes.With whom were the jails and courts overloaded?
A With prisoners. B With arrested demonstrators.
C With criminals. D With protestors.What is the attitude of Governor Stanforth Thumper toward the power project and the demonstration?
A stubborn. B insistent. C insolvable. D remissible.