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问题 选择题

下列体温恒定的生物是（　　）

①青蛙   ②蝗虫    ③企鹅    ④金鱼．

A．①

B．②

C．③

D．④

答案

鸟类和哺乳动物，它们的体表大都被毛（羽毛），循环路线有体循环和肺循环，体内有良好的产热和散热的结构，所以能维持正常的体温，为恒温动物，③企鹅属于鸟类属于恒温动物；而①青蛙是两栖动物，②蝗虫是节肢动物，④金鱼属于鱼类，它们的体温随外界环境的变化而变化，都属于变温动物．

故选C．

多项选择题

喉肌包括（）

A.后环杓肌（成对）

B.侧环杓肌（成对）

C.甲杓肌（成对）

D.环甲肌（成对）

E.杓状软骨间肌（单个）
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单项选择题 案例分析题

From childhood to old age, we all use language as a means of broadening our knowledge of ourselves and the world about us. When humans first 1 , they were like newborn children, unable to use this 2 tool. Yet once language developed, the possibilities for human kind’s future 3 and cultural growth increased.

Many linguists believe that evolution is 4 for our ability to produce and use language. They 5 that our highly evolved brain provides us 6 an innate language ability not found in lower 7 . Proponents of this innateness theory say that our 8 for language is inborn, but that language itself develops gradually, 9 a function of the growth of the brain during childhood. Therefore there are critical 10 times for language development.

Current 11 of innateness theory are mixed, however, evidence supporting the existence of some innate abilities is undeniable. 12 , more and more schools are discovering that foreign languages are best taught in 13 grades. Young children often can learn several languages by being 14 to them, while adults have a much harder time learning another language once the 15 of their first language have become firmly fixed.

16 some aspects of language are undeniably innate, language does not develop automatically in a vacuum. Children who have been 17 from other human beings do not possess language. This demonstrates that 18 with other human beings is necessary for proper language development. Some linguists believe that this is even more basic to human language 19 than any innate capacities. These theorists view language as imitative, learned behavior. 20 , children learn language from their parents by imitating them. Parents gradually shape their child's language skills by positively reinforcing precise imitations and negatively reinforcing imprecise ones.

请在4处填上正确答案（）

A.essential

B.available

C.reliable

D.responsible
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