大学英语四级完形填空练习与解析
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 gradu ……此处隐藏711个字……ns构成，构造;constitutions宪法，章程。
16.A
分析上下文的逻辑关系，从句意思是：语言的某些方面肯定是先天的。主句意思是：语言不会在与人隔绝的状况下自行发展。前后应为转折关系。
17.D
此句意为：与人隔绝的儿童不能掌握好一门语言。isolated孤立的，与人隔绝的;distinguished区别的，杰出的;different不同的;protected受到保护的。
18.D
此句总结前几句，意为：必须通过与他人交往，语言才能够发展。interaction相互作用;exposition暴露;comparison比较;contrast对比。
19.A
根据分析，本句中的“this”和“even more basic”分别指代上句的“interaction with other human beings”和“necessary”，此处所填词对应上文中的language development。也就是说，language acquisition语言习得。appreciation欣赏,感激;requirement要求;alternative转移，转变，转换。
20.C
本句功能是以另一种方式解释前文中的“imitative, learned behavior.(模仿性的后天行为)”。In other words换言之，换句话说;As a result结果是;After all毕竟;Above all首先。
