问一个细节题和一个主旨题

bunnyfdu2015 · 发表于 2014-6-30 15:07:44

Anthropologists once thought that the ancestors of modern humans began to walk upright because it freed their hands to use stone tools ,which they had begum to make as the species evolved a brain of increased size and mental capacity. But discoveries of the three-million-year-old fossilized remains of our hominid ancestor Australopithecus have yielded substantial anatomical evidence that upright walking Appeared prior to the dramatic enlargement of the brain and the development of stone tools. Walking on two legs in an upright posture (bipedal locomotion) is a less efficient proposition than walking on all fours (quadrupedal locomotion) because several muscle groups that the quadruped uses for propulsion must instead to provide the biped the biped with stability and control. The shape and configuration of various bones must likewise be modified to allow the muscles to perform these functions in upright walking. Reconstruction of the pelvis (hipbones) and femur (thighbone) of "Lucy", a three-million-year-old skeleton that is the most complete fossilized skeleton from the australopithecine era, has shown that they are much more like he corresponding bones of the modern human than like those of the most closely related living primate, the quadrupedal chimpanzee. Lucy's wide, shallow pelvis is actually better suited to bipedal walking than is the rounder, bowl-like pelvis of the modern human, which evolved to form the larger birth canal needed to accommodate the head of a largebrained human infant .By contrast, the bead of Lucy's baby could have been no larger than that of a baby chimpanzee.

If the small-brained australopithecines were not toolmakers, what evolutionary advantage did they gain by walking upright? One theory is that bipedality evolved in conjunction with the nuclear family: monogamous parents cooperating to care for their offspring. Walking upright permitted the father to use his hands to gather food and carry it to his mate from a distance, allowing the mother to devote more time and energy to nurturing and protecting their children. According to this view, the transition to bipedal walking may have occurred as long as ten million years ago, at the time of the earliest hominids, making it a crucial initiating event in human evolution

1.according to the passage ,the hominid australopithecine most closely resembled a modern human with respect to which of the following characteristics?

	Brain size
	Tool making ability
	Shape of the pelvis
	Method of locomotion
	Preference for certain foods

选D，怎么都觉得是C啊，回原文哪里找啊？

2.the primary purpose of the passage is to

	present an interpretation of the chrono-logical relationship between bipedal locomotion and certain other key aspects of human evolution
	compare the evolutionary advantages and disadvantages of bipedal locomotion to those of quadrupedal locomotion
	argue that the transition to a nuclear family structure was a more crucial step in human evolution than was the develop ment of stone tools
	analyze anatomical evidence of bipedal locomotion to show that the large brain of modern humans developed at a later stage of evolution than was previously believed
	use examples of muscle and bone structure to illustrate the evolutionary differences between modern humans,australopithecines ,and chimpanzees

选D，我选的C

问一个细节题和一个主旨题

所属分类: GMAT考试

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