In the early 1960s Wilt Chamberlain was one of only three players in the National Basketball Association (NBA) listed at over seven feet. If he had played last season, however, he would have been one of 42. The bodies playing major professional sports have changed dramatically over the years, and managers have been more than willing to adjust team uniforms to fit the growing numbers of bigger, longer frames.

       在20世纪60年代早期，Wilt Chamberlain是美国国家篮球协会中仅有的身高超过7英尺的三个人之一。可是如果他参加了上个赛季的话，他就变成了42分之一了。这些年来，参加各种主要职业赛事的球员的身高发生了很大的改变，经理人十分乐意调整队员的运动服来适应队员们更壮，更高的身材。

        The trend in sports, though, may be obscuring an unrecognized reality: Americans have generally stopped growing.     Though typically about two inches taller now than 140 years ago, today’s people — especially those born to families who have lived in the U.S. for many generations — apparently reached their limit in the early 1960s. And they aren’t likely to get any taller. “In the general population today, at this genetic, environmental level, we’ve pretty much gone as far as we can go,” says anthropologist William Cameron Chumlea of Wright State University. In the case of NBA players, their increase in height appears to result from the increasingly common practice of recruiting players from all over the world.

        但是，体育界的这种趋势可能蒙蔽了一个没有被承认的现实：美国人基本上停止生长了。虽然现在人们比140年前高了2英寸，但是显然，在二十世纪60年代早期，已经到达了他们的身高的极限 —— 特别是那些出生在已移民美国很多代的那些家庭的人。他们已经不可能再长得更高了。“在这个基因和环境的条件下，现在整体的人们已经长到我们能够达到的范围了，”Wright州大学的人类学家William Cameron Chumlea说道。而对于NBA球员来说，他们身高增长的原因主要在于现在从全球招募球员已经成为了一种普遍的做法。

        Growth, which rarely continues beyond the age of 20, demands calories and nutrients — notably, protein — to feed expanding tissues. At the start of the 20th century, under-nutrition and childhood infections got in the way. But as diet and health improved, children and adolescents have, on average, increased in height by about an inch and a half every 20 years, a pattern known as the secular trend in height. Yet according to the Centers for Disease Control and Prevention, average height — 5′9″ for men, 5′4″ for women — hasn’t really changed since 1960.

       身高的增长一般在20岁以后就停止了，长高需要热量和营养物质——主要是蛋白质——以供应身体组织的扩展。在20世纪初的时候，营养不良和儿童疾病影响了人们身体的长高。但是随着饮食和健康状况的改进，儿童和青少年每20年平均长高了约1.5英寸，这是众所周知的身高长期趋势。但是，疾病控制和预防中心认为自从20世纪60年代以来，人们的平均身高——男性5英尺9英寸，女性5英尺4英寸——并没有发生很大的变化。

       Genetically speaking, there are advantages to avoiding substantial height. During childbirth, larger babies have more difficulty passing through the birth canal. Moreover, even though humans have been upright for millions of years, our feet and back continue to struggle with bipedal posture and cannot easily withstand repeated strain imposed by oversize limbs. “There are some real constraints that are set by the genetic architecture of the individual organism,” says anthropologist William Leonard of Northwestern University.

        从遗传的角度来说，防止身材过高也有一些优势。在产妇分娩的过程中，个子大的孩子通过产道的困难更大。此外，尽管人类直立行走已达百万年之久，我们的脚和背总是很费劲地保持两脚站立的姿势、难以经受过大的身材带来的反复巨大压力。“每种生物的基因结构中都有一些限制，这是真实存在的”西北大学的人类学家William Leonard说。

      Genetic maximums can change, but don’t expect this to happen soon. Claire C. Gordon, senior anthropologist at the Army Research Center in Natick, Mass., ensures that 90 percent of the uniforms and workstations fit recruits without alteration. She says that, unlike those for basketball, the length of military uniforms has not changed for some time. And if you need to predict human height in the near future to design a piece of equipment, Gordon says that by and large, “you could use today’s data and feel fairly confident.”

    基因的最大值可以改变，但是不要期望它们会很快地改变。位于Natick的军队研究中心高级人类学家Claire C. Gordon保证说90%的制服和工作服适合新招募的成员，不需改动。她指出，与篮球队服的情况不同，军装的尺寸已经有很多年没有变化了。如果你为了设计一款新的设备而需要预测人类在不久的将来的身高变化，Gordon认为基本上“你可以采用目前的数据，而且还可以感觉非常自信。”

31. Wilt Chamberlain is cited as an example to_______________.
[A] illustrate the change of height of NBA players.
[B] show the popularity of NBA players in the U.S..
[C] compare different generations of NBA players.
[D] assess the achievements of famous NBA players.
Wilt Chamberlain的例子用来_______________.
[A] 说明NBA球员的身高变化
[B] 说明NBA球员在美国很受欢迎
[C] 比较不同年代的NBA球员
[D] 评估著名NBA球员的成就

32. Which of the following plays a key role in body growth according to the text?
[A] Genetic modification.
[B] Natural environment.
[C] Living standards.
[D] Daily exercise.
根据文章，下面哪一项是身体长高的关键因素？
[A] 基因改变
[B] 自然环境
[C] 生活水平
[D] 日常锻炼

33. On which of the following statements would the author most probably agree?
[A] Non-Americans add to the average height of the nation.
[B] Human height is conditioned by the upright posture.
[C] Americans are the tallest on average in the world.
[D] Larger babies tend to become taller in adulthood.
作者会同意下面哪一项说法的观点？
[A] 非美国人的加入使得该国人口的平均身高变高
[B] 人类身高受到直立姿势的影响
[C] 美国人的平均身高在世界上是最高的
[D] 个子大的婴儿往往成人后也比其他人更高

34. We learn from the last paragraph that in the near future_______________.
[A] the garment industry will reconsider the uniform size.
[B] the design of military uniforms will remain unchanged.
[C] genetic testing will be employed in selecting sportsmen.
[D] the existing data of human height will still be applicable.
我们可以从最后一段中得知，在不久的将来_______________.
[A] 服装业将重新制定制服尺寸
[B] 军队制服的设计不会有很大变化
[C] 基因测试会被用于遴选运动员
[D] 现有的人类身高数据将可以适用

35. The text intends to tell us that_______________.
[A] the change of human height follows a cyclic pattern.
[B] human height is becoming even more predictable.
[C] Americans have reached their genetic growth limit.
[D] the genetic pattern of Americans has altered.
本文想要告诉我们的是_______________.
[A] 人类身高的改变遵循一个循环的模型
[B] 人类身高变得更有可预测性
[C] 美国人达到了基因上的生长极限
[D] 美国人的基因模型已经改变