19. When it is struck, a tuning fork produces an almost pure tone, retaining its pitch over a long period of time。

　　19.音叉被敲击时，产生几乎纯质的音调，其音量经久不衰。

　　20. Although pecans are mostplentiful in the southeastern part of the United States, they are foundas far north as Ohio and Illinois。

　　20.虽然美洲山河桃树最集中于美国的东南部但是在北至俄亥俄州及伊利诺州也能看见它们。

　　21. Eliminating problems by transferring the blame to others is often called scape-goating。

　　21.用怪罪别人的办法来解决问题通常被称为寻找替罪羊。

　　22. The chief foods eaten in any country depend largely on what grows best in its climate and soil。

　　22.一个国家的主要食物是什么，大体取决于什么作物在其天气和土壤条件下生长得最好。

　　23. Over a very large numberof trials, the probability of an event’s occurring is equal to theprobability that it will not occur。

　　23.在大量的实验中，某一事件发生的几率等于它不发生的几率。

　　24. Most substance contractwhen they freeze so that the density of a substance’s solid is higherthan the density of its liquid。

　　24.大多数物质遇冷收缩，所以他们的密度在固态时高于液态。

　　25. The mechanism by which brain cells store memories is not clearly understood。

　　25.大脑细胞储存记忆的机理并不为人明白。

　　26. By the middle of thetwentieth century, painters and sculptors in the United States hadbegun to exert a great worldwide influence over art。

　　26.到了二十一世纪中叶，美国画家和雕塑家开始在世界范围内对艺术产生重大影响。

　　27. In the eastern part of New Jersey lies the city of Elizabeth, a major shipping and manufacturing center。

　　27.伊丽莎白市，一个重要的航运和制造业中心，坐落于新泽西州的东部。

　　28. Elizabeth Blackwell, thefirst woman medical doctor in the United States, founded the New YorkInfirmary, an institution that has always had a completely femalemedical staff。

　　28. Elizabeth Blackwell，美国第一个女医生，创建了员工一直为女性纽约诊所。

　　29. Alexander Graham Bellonce told his family that he would rather be remembered as a teacher ofthe deaf than as the inventor of the telephone。

　　29. Alexander Graham Bell曾告诉家人，他更愿意让后人记住他是聋子的老师，而非电话的发明者。

　　30. Because its leaves remain green long after being picked, rosemary became associated with the idea of remembrance。

　　30.采摘下的迷迭香树叶常绿不衰，因此人们把迷迭香树与怀念联系在一起。

　　31. Although apparently rigid, bones exhibit a degree of elasticity that enables the skeleton to withstand considerable impact。

　　31.骨头看起来是脆硬的，但它也有一定的弹性，使得骨骼能够承受相当的打击。

　　32. That xenon could not FORM chemical compounds was once believed by scientists。

　　32.科学家曾相信：氙气是不能形成化合物的。

　　33. Research into thedynamics of storms is directed toward improving the ability to predictthese events and thus to minimize damage and avoid loss of life.　       33.对风暴动力学的研究是为了提高风暴预测从而减少损失，避免人员伤亡。

　　34. The elimination ofinflation would ensure that the amount of money used in repaying a loanwould have the same value as the amount of money borrowed.       34.消除通货膨胀应确保还贷的钱应与所贷款的价值相同。

　　35. Futurism, an earlytwentieth-century movement in art, rejected all traditions andattempted to glorify contemporary life by emphasizing the machine andmotion。

　　35.未来主义，二十世纪早期的一个艺术思潮。拒绝一切传统，试图通过强调机械和动态来美化生活。

　　36. One of the wildest andmost inaccessible parts of the United States is the Everglades wherewildlife is abundant and largely protected。

　　36. Everglades是美国境内最为荒凉和人迹罕至的地区之一，此处有大量的野生动植物而且大多受(法律)保护。

　　37. Lucretia Mott’sinfluence was so significant that she has been credited by someauthorities as the originator of feminism in the United States。

　　37. Lucretia Mott’s的影响巨大，所以一些权威部门认定她为美国女权运动的创始人。

　　38. The activities of the international marketing researcher are frequently much broader than those of the domestic marketer。