参考答案：

　　这些年，家庭也在发生着变化。单亲家庭或父母都有工作的家庭不断增加。这样一来，孩子可能在家庭受到的监督就可能比过去传统家庭要少。有人认为缺乏父母的监督会影响孩子的犯罪率。儿童犯罪的其他一些确凿原因还包括在学校的挫折与失败，药物和酒精更加容易得到，以及对孩子受到的虐待与忽视越来越多。所有这一切都会增加儿童犯罪的可能性，虽然其中的直接因果关系还不确定。

　　Environmentalists say that it is very important for us to protect wild animals, if we need the earth to supply the human being continuously. These experts say that we must understand the fundamental relation between ourselves and wild animals and plants in our environmental supplying system. They point out that no one is sure to know which kind of animals is likely to be useful to us in the future.

　　参考答案：

　　环境科学家们说,如果要使地球继续供养人类生存，保护野生生物是极为重要的。这些专家说我们必须明白在我们的这个环境供养系统中，我们自己与野生动植物之间的重要联系。他们指出，没有人有把握地知道这些动植物中的哪一种将来可能对我们有用。

　　The average number of authors on scientific papers is sky-rocketing. That’s partly because labs are bigger, problems are more complicated, and more different subspecialties are needed. But it’s also because U.S. government agencies have started to promote “team science”. As physics developed in the post-World War Ⅱ era, federal funds built expensive national facilities, and these served as surfaces on which collaborations could crystallize naturally.

　　Yet multiple authorship — however good it may be in other ways — presents problems for journals and for the institutions in which these authors work. For the journals, long lists of authors are hard to deal with in themselves. But those long lists give rise to more serious questions when something goes wrong with the paper. If there is research misconduct, how should the liability be allocated among the authors? If there is an honest mistake in one part of the work but not in others, how should an evaluator aim his or her review?

　　Various practical or impractical suggestions have emerged during the long-standing debate on this issue. One is that each author should provide, and the journal should then publish, an account of that author’s particular contribution to the work. But a different view of the problem, and perhaps of the solution, comes as we get to university committee on appointments and promotions, which is where the authorship rubber really meets the road. Half a lifetime of involvement with this process has taught me how much authorship matters. I have watched committees attempting to decode sequences of names, agonize over whether a much-cited paper was really the candidate’s work or a coauthor’s, and send back recommendations asking for more specificity about the division of responsibility.

　　Problems of this kind change the argument, supporting the case for asking authors to define their own roles. After all, if quality judgments about individuals are to be made on the basis of their personal contributions, then the judges better know what they did. But if questions arise about the validity of the work as a whole, whether as challenges to its conduct or as evaluations of its influence in the field, a team is a team, and the members should share the credit or the blame.