Our ape-men forefathers had no obvious natural weapons in the struggle for survival in the open. They had neither the powerful teeth nor the strong claws of the big cats. They could not【C1】______with the bear, whose strength, speed and claws【C2】______an impressive ""small fire"" weaponry. They could not even defend themselves【C3】______running swiftly like the horses, zebras or small animals. If the ape-men had attempted to compete on those terms in the open, they would have been【C4】______to failure and; extinction. But they were【C5】______with enormous concealed advantages of a kind not possessed by any of their competitors.
In the search【C6】______the pickings of the forest, the ape-men had【C7】______efficient stereoscopic vision and a sense of colour that the animals of the grasslands did not possess. The ability to see clearly at close range permitted the ape-men to study practical problems in a way that lay far【C8】______the reach of the original inhabitants of the grassland. Good long distance sight was【C9】______another matter. Lack of long-distance vision had not been a problem for forest-dwelling apes and monkeys because the higher the viewpoint, the greater the range of sight so【C10】______they had had to do was climb a tree. Out in the open, however, this simple solution was not【C11】______Climbing a hill would have helped, but in many places the ground was flat. The ape-men【C12】______the only possible solution. They reared up as high as possible on their hind limbs and began to walk upright.
This vital change of physical position brought about considerable disadvantages. It was extremely unstable and it meant that the already slow ape-men became slower still.【C13】______, they persevered and their bone structure gradually became【C14】______to the new, unstable position that【C15】______them the name Homo erectus, upright man."
单选题 【C1】
【正确答案】 B
【答案解析】当表示“相比，匹敌”的意思时，match，rival和equal均为及物动词。compare常与with连用，意为“与……比较；比得上”，如：Walking can’t compare with flying．(走路比不上飞行。)因此，答案为B。
单选题 【C2】
【正确答案】 D
【答案解析】联系上下文，力气、速度和爪牙为熊提供了天生的“武器”，“provide供应，提供”符合要求，为正确答案。
单选题 【C3】
【正确答案】 C
【答案解析】defend意为“防护，辩护，防卫”，defend…by doing sth．为习惯用法，其中by表示“靠，用，通过(方法、手段)”。
单选题 【C4】
【正确答案】 B
【答案解析】be doomed to意为“注定”，为习惯用法，后接名词或不定式。be doomed tofailure(to fail)表示注定要失败。因此，答案为B。
单选题 【C5】
【正确答案】 D
【答案解析】endow意为“赋予，捐赠”，与with搭配时一般用于被动式，即be endowedwith，如：She is endowed with great writing ability.(她具有杰出的写作天赋。)故D项符合题意。
单选题 【C6】
【正确答案】 A
【答案解析】search作名词时意为“搜索；查访；搜寻”，常与of，for连用。in search of(=in one’s／the search for)意为“为了寻找，追求”，但在in search of中，search前不能带冠词the。所以，A为正确答案。
单选题 【C7】
【正确答案】 C
【答案解析】四个选项均含有“发展，前进”的意思。但只有develop与vision和colour搭配最恰当。
单选题 【C8】
【正确答案】 C
【答案解析】本题考查固定搭配。beyond the reach of sth．表示“达不到的，力所不及的；不能理解的”。
单选题 【C9】
【正确答案】 B
【答案解析】A、C、D均不与another连用，quite意为“相当，完全，十分，彻底”，表示程度，可用在限定词another前，如：That’s quite another matter．(那完全是另外一回事。)
单选题 【C10】
【正确答案】 D
【答案解析】联系上下文，只有all符合句意。因此，正确答案为D。
单选题 【C11】
【正确答案】 B
【答案解析】从空前的however表示的转折意义可知句子表否定。A、D可从词义上排除。enough为常用词，除表示“足以满足需要的”外，还含有“数量很多使人感到心满意足的”之意；sufficient用于正式文体，侧重指“分量或数量充分的”。显然，B项更加合适。
单选题 【C12】
【正确答案】 D
【答案解析】根据空后的“the only possible solution”可排除A、C；adopt意为“采取，采用”，常与method，idea和report等搭配；take与solution搭配，表示“采取……解决方法(方案)”，符合题意。故本题选D。
单选题 【C13】
【正确答案】 A
【答案解析】联系上下文语境，该空所在句与前一句构成转折关系，从意义上分析，however符合，且其后常用逗号与句子其他成分隔开。因此，答案为A。
单选题 【C14】
【正确答案】 A
【答案解析】be(become，grow，get)accustomed to是习惯用法，表示“(变得)习惯于”，后跟sth．／doing sth．。A项无论从句意还是结构上都符合要求，据此，答案为A。
单选题 【C15】
【正确答案】 D
【答案解析】句中that引导定语从句，修饰position。此处选择后可接双宾语的动词，D项符合要求，如：Stephen Hawking's achievements earned him the acclaim of the entirescientific community．(斯蒂芬·霍金的成就使他赢得了整个科学界的赞扬。)