[单选题]In the past, falling oil prices have given a boost to the world economy, but recent forecasts for global growth have been toned down, even as oil prices sink lower and lower.Does that mean the link between lower oil prices and growth has weakened? Some experts say there are still good reasons to believe cheap oil should heat up the world economy. Consumers have more money in their pockets when they’re paying less at the pump.They spend that money on other things, which stimulates the economy. The biggest gains go to countries that import most of their oil like China, Japan, and India.But doesn’t the extra money in the pockets of those countries’consumers mean an equal loss in oil producing countries, cancelling out the gains? Not necessarily, says economic researcher Sara Johnson.“Many oil producers built up huge reserve funds when prices were high, so when prices fall they will draw on their reserves to support government spending and subsidiesfor their consumers.” But not all oil producers have big reserves, In Venezuela, collapsing oil prices have sent its economy into free-fall. Economist Carl Weinberg believes the negative effects of plunging oil prices are overwhelming the positive effects of cheaper oil.The implication is a sharp decline in global trade, which has plunged partly because oil-producing nations can’t afford to import as much as they used to. Sara Johnson acknowledges that the global economic benefit from a fall in oil prices today is likely lower than it was in the past.One reason is that more countries are big oil producers now, so the nations suffering from the price drop account for a larger share of the global economy. Consumers, in the U.S.at least, are acting cautiously with the savings they’re getting at the gas pump, as the memory of the recent great recession is still fresh in their mind.And a number of oil-producing countries are trimming their gasoline subsidies and raising taxes, so the net savings for global consumers is not as big as the oil price plunge might suggest. Why haven’t falling oil prices boosted the global economy as they did before?
[单选题]Sea horses are unusual parents. The female sea horses lay the eggs,but unlike other creatures,it’s the males that give birth to the young. Male sea horse have a fold of skin on their bellies that forms a pocket,called a brood pouch. During the breeding season,the sea horse’s pouch swells to receive eggs. A female sea horse lays up to 200 eggs at a time in the pouch. Then she swims off,leaving her male partner to care for the developing eggs and give birth to young sea horses. The female will return every day to check on her mate and the eggs,but she doesn’t stay long,nor does she take part in the birth. It takes from two to six weeks for the eggs in the male’s pouch to develop. During this time the male avoids open water and hides in sea grass. His big pouch makes it difficult for him to swim,so the male often uses his tail to grasp a piece of sea grass. Firmly,gripping the grass,he will stay perfectly still for hours or even days. The male sea horse will change his color to blend with his surroundings and avoid being seen by predators who will try to eat him or poke holes in his pouch to get the eggs. The eggs hatch inside the male’s pouch. When the babies begin moving around,the male sea horse knows it’s time for them to be born. He grabs a sea grass stem with his tail and begins rocking,bending,and stretching his body back and forth. This causes the opening to enlarge until it is wide enough for the first baby sea horse to shoot out. The father sea horse continues rocking,bending,and stretching his body so that the rest of the babies can be born. Sometimes he has to press his pouch against a rock or some stiff seaweed to force the young out. Sea horse babies are born in groups of five or more. Sometimes it takes two days for the father sea horse to give birth to all his young. He is very tired when it’s over. Soon after giving birth to one brood,the male will approach his mate and show her his empty pouch. This tells her he is ready to receive eggs again. 36. What part does the female sea horse play in having babies?
[单选题]Americans are proud of their variety and individuality, yet they love and respect few things more than a uniform, whether it is the uniform of an elevator operator or the uniform of a five-star general. Why are uniforms so popular in the United States? Among the arguments for uniforms, one of the first is that in the eyes of most people they look more professional than civilian (百姓的) clothes.People have become conditioned to expect superior quality from a man who wears a uniform.The television repairman who wears a uniform tends to inspire more trust than one who appears in civilian clothes.Faith in the skill of a garage mechanic is increased by a uniform.What easier way is there for a nurse, a policeman, a barber, or a waiter to lose professional identity (身份) than to step out of the uniform? Uniforms also have many practical benefits.They save on other clothes.They save on laundry bills.They are tax—deductible (可减税的).They are often more comfortable and more durable than civilian clothes. Primary among the arguments against uniforms is their lack of variety and the consequent loss of individuality experienced by people who must wear them.Though there are many types of uniforms, the wearer of any particular type is generally stuck with it, without change, until retirement.When people look alike, they tend to think, speak, and act similarly, on the job at least. Uniforms also give rise to some practical problems.Though they are long—lasting, often their initial expense is greater than the cost of civilian clothes.Some uniforms are also expensive to maintain, requiring professional dry cleaning rather than the home laundering possible with many types of civilian clothes. People are accustomed to thinking that a man in uniform _______.
[单选题]A recent report on population trend conducted by the think tank of the Worldwatch Institute identifies signs of slowing growth in some countries.It says populations in 32 countries-all in the industrialized world-have stabilized because of declining birthrates.But in a handful of developing countries where population is slowing, the cause isn’t something to 46 , because more people are dying. This trend is called “population fatigue,” and it’s beginning in many of the developing countries that have experienced 47 birthrates and sharp population growth for several decades.Governments in these countries are now having trouble dealing with feeding, housing and educating an increasing number of children, while at the same time confronting the falling water table,deforestation and soil erosion that rapid population growth brings.In these countries any new threat-infectious disease, drought or famine-can become a full-blown crisis.AIDS is a case 48.WHO estimates calculate that one-quarter of the adult population of Zimbabwe and Botswana are infected with the AIDS virus, 49 ,these countries stands to lose at least one-quarter of their labor force in the next decade from AIDS alone, a situation 50 since the yellow fever swept through Europe in the 14 th century.Social unrest is also increasing in these countries.One example is the 51 conflict between the Tutsis and the Hutus in Rwanda, where population pressures reduced cropland 52 where it could no longer feed those who lived on it.Demands on the world fisheries and shared water resources are likely to spark similar conflicts.Already the waters of the Nile are so heavily used that little reaches the Mediterranean, so any increase in demand or 53 in allocation will also increase tensions. The bottom line is that human population growth is 54 to slow one way or the other. Developing societies will either recognize problems on the horizon and act to encourage smaller families-or unchecked births will have their 55 in rising death rates.