在英语日益重要的今天，学好英语成了大多数学生的首要目标。为帮助大学生高效的学习英语。特收集以下练习：
56. Supporters of the Star Wars defense system hope that this would not only protect a nation against an actual nuclear attack, but would be enough of a threat to keep a nuclear war from ever happening.
57. Neither would it prevent cruise missiles or bombers, whose flights are within the Earth’s atmosphere, from hitting their targets.
58. Civil rights activists have long argued that one of the principal reasons why Blacks, Hispanics, and other minority groups have difficulty establishing themselves in business is that they lack access to the sizable orders and subcontracts that are generated by large companies.
59. During the nineteenth century, she argues, the concept of the “useful” child who contributed to the family economy gave way gradually to the present day notion of the “useless” child who, though producing no income for, and indeed extremely costly to its parents, is yet considered emotionally “ priceless”.
60. Well established among segments of the middle and upper classes by the mid-1800’s, this new view of childhood spread throughout society in the late nineteenth and early twentieth centuries as reformers introduced child labor regulations and compulsory education laws predicted in part on the assumption that a child’s emotional value made child labor taboo.
56、星球大战防御系统的撑持者们但愿它不仅能呵护一个蒙受核抨击袭击的国家，也但愿它能成为使核抨击袭击永不贰生的足够威胁。
57、它也不能防止轨道在地球大气层以内的洲际导弹和耗炸秘射中方针。
58、人平易近勾当家一向认为黑人和拉丁佳丽难以在生意上安身的原因是因为他们难以取得大公司的大宗定单和分包合同。
59、她认为十九世纪给家庭经济作出进献的孩子才“有用”的概念慢慢改变了，今天提到那些没有挣取收入的“无用”孩子，甚至还要花销良多，仍然在激情上被认为是无价的。
60、这种关于孩子的不雅概念到19世纪时已在中上阶级中成立，康复19世纪末20世纪初在社会上普遍传布，那时更始者们奉行童工划定和义务教育法，部门来历于孩子的激情价值的假设，这都使得使用童工被禁止了。