21．A blood test might even be fairer than the crude substitutes we use instead to judge and choose among people: It would zero in on the trait we really need to discriminate about and reduce discrimination on the basis of traits that are irrelevant.
句意：与我们用来评判和挑选人的拙劣的替代方式相比，血液测试甚至可能更合理：这将使我们把注意力集中在我们确实需要的特性上，根据不相关的特性来鉴别和减少歧视。
22. The rapid spread of the Russian wheat aphid to fifteen states in just two years following its 1986 arrival has been attributed in part to the prevalence of alternative host plants that are available when wheat is not.
句意：1986年侵入美国后，俄罗斯麦蚜虫就在两年内迅速传遍15个州，部分原因是，在没有小麦的地方，这些蚜虫能找到大量其他寄生植物。
23．In addition, federal port inspection, although a major source of information on non-indigenous species pathways, especially for agriculture pests, provides data only when such species enter via closely-examined routes.
句意：此外，尽管联邦口岸检查部门是提供外来物种入侵途径相关信息的主要机构，尤其是提供农业害虫的信息，但它们也只是在这些物种通过被密切关注的途径入侵时才提供相关数据。
24．This time the question was not which children were going to what schools but what kind of education society should provide for the students; the goal of high academic performance, which had been revived by criticisms and reforms of the 1950s and early 1960s, began to be challenged by demands for more liberal and free schooling.
句意：这次的问题不是哪种孩子应该上什么学校的问题，而是社会应该向学生提供什么样的教育问题；20世纪50和60年代的批评和改革复兴了取得好学习成绩的培养目标，现在开始受到需要更宽松、更自由的学校教育的挑战。
25．Whites and blacks alike also wanted a curriculum that touched more closely on contemporary social problems and teaching methods that recognized their existence as individual human beings rather than as faceless robots competing for grades.
句意：白人和黑人都希望课程更直接关注当代的社会问题，希望教学方法把他们的存在当作个体的人类，而不是竞争分数的不露面机器人。
26. Primary socialization refers to the training of children during their earliest years, whereas secondary socialization refers to later influences on the development of the child’s personality and learning activities, such as his involvement with teachers and with other children at school.
句意：初始社会化是指孩子出生后的最初几年对他们进行的训练，而中级社会化则是指对孩子个性以及学习活动发展的后来影响，比如在学校与老师和其他同学的相处。
27．Yet the principle behind primary socialization in different societies is the same: the development of social values must be achieved in an environment of love and security, as is found in the ideal family anywhere in the world.
句意：然而，不同的社会隐藏于初始社会化之后的原则都是相同的：要想实现社会价值观的发展，必须提供一个仁爱而且安全的环境，如同世界任何地方的理想家庭中所感受到的一样。
28．Indeed, the cycle may be repeated if such a person in time marries, has a family of his own, and treats his children in the same way; nonetheless, there is no reason to suppose that all children of unsatisfactory marriages are treated in such a way or fail to overcome the difficulties they have as children.
句意：实际上，如果这种人适时结婚，组建自己的家庭，并且以同样的方式对待他的孩子，那么这种循环就会再现；但是，我们没有理由认为：所有不幸婚姻家庭的孩子都受到这种方式的对待，或是没能克服他们作为孩子所面临的困难。
29．Some social scientists have even suggested that the isolated nuclear family, as it exists in Western industrialized societies, is to blame for the social ills found in those societies; they claim that in the past more support was offered from the wider kin network and from the community as a whole—as is still the case in less-developed parts of the world.
句意：一些社会科学家甚至指出：独立的核心家庭，就像西方工业化国家所具有的那样，应该为那些国家显现的社会问题而受到谴责；他们声称：过去，广泛的家族网络以及整个社会对这种现象给予了更多的支持——在世界上的不发达国家，这种现象仍然存在。
30. For the first time in the scientific community, there is total agreement that the activity of humans is at least partly responsible for the problem—specifically the emission of greenhouse gases like carbon dioxide, which is released by the burning of wood, coal and petroleum products.
句意：人类的行为至少应该对温度的升高承担部分责任，尤其像二氧化碳这种温室气体的排放，二氧化碳是木材、煤以及石油产品的燃烧而释放出来的，科学界首次对这个问题达成共识。
