问题 多选题

下列有关生物多样性的有关说法,不正确的是(  )

A.我国是世界上生物多样性最丰富的国家之一

B.每种生物都是一个丰富的基因库

C.生态系统的多样性仅指生物种类的多样性

D.保护生物多样性的根本措施是建立自然保护区

答案

A、生物的多样性包括基因的多样性、生物种类的多样性、生态系统的多样性,我国是世界上生物多样性最丰富的国家之一.不符合题意.

B、每个物种都是一个独特的基因库.生物种类的多样性是由基因的多样性决定的,所以其实质就是基因多样性.不符合题意.

C、生态系统是生物与环境构成的统一的整体,生态系统的多样性包括生物种类的多样性和生活环境的多样性,符合题意.

D、威胁生物生存的原因有栖息地被破坏、偷猎、外来物种入侵、环境污染、其他原因等.其中最主要的原因就是栖息地等生态环境的破坏以及偷猎.保护生物的栖息环境,保护生态系统是保护生物多样的根本措施.符合题意.

故选:CD

填空题

Every now and then a study comes along whose chief interest lies in how peculiarly askew its findings seem to be from the common perception of things. Sometimes, of course, the "surprising new study" itself turns out to be off in some way. But if the data are fundamentally sound, then what you really want to know is why sensible people hold such a contrary view.

41___________________. Researchers took a closer look at an earlier study that had been widely interpreted, when it was first published in 2000, as proof that the homework monster was growing, and insatiable. A Time magazine cover article spawned a minigenre of trend stories, all peopled by pale, exhausted kids and bewildered boomer parents whose own homework memories seemed to encompass only felt puppets and shoe-box dioramas. But the new report points out that while the amount of time schoolchildren 12 and under devoted to study at home did indeed grow between 1981 and 1997, the increase was small: an average of 23 minutes per week. 42___________________.

So why do so many parents seem to think otherwise One answer is that the real increase in homework that has been documented is among younger children. In 1981, for instance, one-third of 6- to 8-year-olds had some homework; one-half did in the late 90’s. 43___________________.

Since children 6 to 8 are the ones we particularly like to think of as engaged in unstructured play--we imagine them riding bikes in the honeyed light of waning afternoons, even when what they might well be doing, in the absence of homework, is watching TV-homework for them seems like one of those heavy-handed incursions on the freedom of childhood.

44___________________. These children go to elite private schools or to demanding public ones where the competitive pressures are such that they either really do have hours of homework each night or take hours finishing it because they (or their parents) are so anxious that it be done well. They come from the demographic that makes a cultural, almost a. moral, ideal of enrolling children in soccer and oboe lessons and karate and ballet, and so their time really is at a premium. 45___________________.

A. Moreover, 20 percent fewer children between the ages of 9 and 12 were doing homework at all in 1997 than in 1981. And high-school students spent no more time on homework than they did in previous decades.

B. That is certainly the question raised by a Brookings Institution report released last month showing that the amount of time kids devote to homework has not, in fact, significantly increased over the last two decades.

C. Behind the seeming contradictions of steady homework levels and the anti-homework backlash, in other words, is the reality of social class.

D. They are likely to have busy professional parents, oversubscribed themselves but with an investment in seeing their children produce book reports of a kind that teachers, counselors and, in time, college admissions boards will find impressive.

E. Anti-homework crusades are not new-in 1901, for example, California passed a law abolishing homework for grades one through eight-but they have usually been led by the same kinds of people, which is to say, elites.

F. Since parents are more likely to have to supervise a first or second grader doing homework than an older child, the earlier launching of a homework regimen might feel like a disproportionate increase in the parental workload.

G. But the bigger answer, I suspect, is that the parents we tend to hear from in the press, at school-board meetings and in Internet chat groups, the parents with elaborated, developmentally savvy critiques of standards and curriculums, are parents whose children really are experiencing a time crunc

45

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