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The puzzle of left-handedness seems to be a modest growth area in current research. One of the latest proposals links left-handedness both with an overproduction of the male hormone and with deficiencies in the body’s automatic defense mechanisms, although it is not clear whether the overproduction of hormone causes the defense defect, or is simply one symptom of a general imbalance. Could this explain why 13 per cent of male children, but only 10 per cent of females, are left-handed?Today, very roughly 10 per cent of the population is left-handed. The odd thing is that this percentage seems to have remained constant throughout history, and indeed throughout human prehistory. From written records, and even painting, researchers can get a guide to the incidence of left-handedness among our recent ancestors.Looking further back, some experts claim to be able to tell from the shaping of flint(打火石) tools whether our Stone Age forebears were left-or right-handed while the habit of cave painters of leaving hand prints (as “signatures”)on walls at least tells us which hand an individual used for marking walls. The evidence suggests that 10 per cent of the population was left-handed.This is a common evolutionary pattern where there are variations that each provides some advantage for the individual that carries them, but not an overwhelming advantage, so that all the variations exist somewhere in the population.A balance is struck in which the proportions of the population in which each version is expressed stay roughly the same form generation to generation - as in the case of blood groups, for example. There must be some advantage, in Darwinian terms, in being a left-hander among a population of predominantly right-handed people. But this is very different from the pattern seen in most animals.Our near relatives, the chimpanzees, also show individual preference for one hand or the other, but half the chimp population is left-handed. Even rats show the same split - 50 per cent left-pawed and 50 per cent right-pawed. Man may not quite be unique among mammals; there have been claims that polar bears are more likely to be left-handed than right, although understandably few experiments have been done with polar bears under laboratory conditions. But by comparison with our cousin apes, it looks as if research into left-handedness in people may be asking the wrong question.The real puzzle is not why 10 per cent of people are left-handed, but why 90 per cent are right-handed. What has happened to the human species, in evolutionary terms, to tilt the balance away from left-handers in favor of right-handers? Why is man the right-handed ape? Nobody has a satisfactory answer. But it is one of the curiosities of scientific research that studies of something seemingly so mundane as left-handedness in people could actually shed new light on human evolution.1.The article suggests that left-handedness might be due to( )2.It appears from the article that ( )3.What do we learn about polar bears?4.What advantage is shown in being a left-hander?5.From the passage, we can guess the word "mundane" in the last paragraph means( ).

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Nowadays, a cellphone service is available to everyone, everywhere. Probably thousands of people have already been using it, but I just discovered it, so I'm going to claim it and also name it: Fake Foning.The technology has been working well for me at the office, but there are infinite applications. Virtually in any public space.Say you work at a big university with lots of talky faculty members buzzing about. Now, say you need to use the restroom. The trip down the hall will take approximately one hour, because a person can’t walk into those talky people without getting pulled aside for a question, a bit of gossip, a new read on a certain line of Paradise Lost.So, a cellphone. Any cellphone. Just pick it up. Don't dial. Just hold that phone to your face and start talking. Walk confidently down the hall engaged in fake conversation, making sure to tailor both the topic and content to the person standing before you whom you are trying to evade.For standard colleague avoidance, I suggest fake chatting about fake business:“Yes, I’m glad you called, because we really need to hammer out the details. What’s that? Yes, I read Page 12, but if you look at the bottom of 4, I think you can see the problem begins right there.”Be engaged in your fake fone conversation. Make eye contact with the people passing, nod to them, gesture keen interest in talking to them at a later time, point to your phone, shrug and move on.Shoppers should consider fake foning anytime they spot a talky neighbor in the produce department pinching (用手捏) unripe peaches. Without your phone at your face, you'd be in for a 20-minute speech on how terrible the world is.One important caution about fake foning. The other day I was fake foning my way past a colleague, and he was actually following me to get my attention. I knew he wanted to ask about a project I had not yet finished. I was trying to buy myself some time, so I continued fake foning with my doctor. “So I don’t need the operation? Oh, doctor, that is the best news.”And then: Brrrrrrng! Brrrrrmg! Brrrrrmg! My phone started ringing, right there while it was planted on my face. My colleague looked at me, and I at him, and naturally I gasped. “What is the matter with this thing?” I said, pulling the phone away to look at it, and then putting it back to my ear.“Hello? Are you still there?” Oops.1.Which of the following statement is INCORRECT?2. What is faking foning?3. In the author’s opinion, in order to make foning look real one has to4. What does the last example show?5. After his phone suddenly began ringing, the author

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During the past generation, the American middle-class family that once could count on hard work and fair play to keep itself financially secure had been transformed by economic risk and new realties. Now a pink slip, a bad diagnosis, or a disappearing spouse can reduce a family from solidly middle class to newly poor in a few months.In just one generation, millions of mothers have gone to work, transforming basic family economics. Scholars, policymakers, and critics of all stripes have debated the social implications of these changes, but few have looked at the side effect: family risk has risen as well. Today’s families have budgeted to the limits of theirs new two-paycheck status. As a result, they have lost the parachuted they once had in times of financial setback - a back-up earner (usually Mom) who could go into the workforce if the primary earner got laid off or fell sick. This “added-worker effect” could support the safety net offered by unemployment insurance or disability insurance to help families weather bad times. But today, a disruption to family fortunes can no longer be made up with extra income from an otherwise-stay-at-home partner.During the same period, families have been asked to absorb much more risk in their retirement income. Steelworkers, airline employees, and now those in the auto industry are joining millions of families who must worry about interest rates, stock market fluctuation, and the harsh reality that they may outlive their retirement money. For much of the past year, President Bush campaigned to move Social Security to a saving-account model, with retirees trading much or all of their guaranteed payments for payments depending on investment returns. For younger families the picture is not any better.Both the absolute cost of healthcare and the share of it borne by families have risen - and newly fashionable health-saving plans are spreading from legislative halls to Wal-Mart workers, with much higher deductibles and a large new dose of investment risk for families’ future health care. Even demographics are working against the middle class family, as the odds of having a weak elderly parent - and all the attendant need for physical and financial assistance - have jumped eight fold in just one generation.From the middle-class family perspective, much of this, understandably, looks far less like an opportunity to exercise more financial responsibility, and a good deal more like a frightening acceleration of the wholesale shift of financial risk onto their already overburdened shoulders. The financial fallout has begun, and the political fallout may not be far behind.1.Today’s double-income families are at greater financial risk in that ( ).2.As a result of Present Bush’s reform, retired people may have( ).3.According to the author, health-savings plans will ( ).4.It can be inferred from the last paragraph that( ).5.Which of the following is the best title for this text?

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