【正文】 created paints by grinding materials such as plants and clay into power and then adding water.，然后加水。　　69. Snow aids farmers by keeping heart in the lower ground levels, thereby saving the seeds from freezing.，因?yàn)樗３值貙油寥赖臏囟?，使種子不致凍死?！　?7. Scientists do not know why dinosaurs became extinct, but some theories postulate that changers in geography, climate, and sea levels were responsible.，但是一些理論推斷是地理，氣候和海平面的變化造成的?！　?5. Although mockingbirds superbly mimic the songs and calls of many birds, they can nonetheless be quickly identified as mockingbirds by certain aural clues.，但人類還是能夠依其聲音上的線索很快識(shí)別它們。　　63. The human skeleton consists of more than two hundred bones bound together by tough and relatively inelastic connective tissues called ligaments.，住些骨頭石油堅(jiān)韌而相對(duì)缺乏彈性的，被稱為韌帶的結(jié)蒂組連在一起。61. Buyers and sellers should be aware of new developments in technology can and does affect marketing activities.，原因很簡(jiǎn)單，因?yàn)榧夹g(shù)能夠并且已經(jīng)影響著營銷活動(dòng)?！　?9. Before staring on a sea voyage, prudent navigators learn the sea charts, study the sailing directions, and memorize lighthouse locations to prepare themselves for any conditions they might encounter.，會(huì)研究航向，記錄的燈塔的位置，以便對(duì)各種可能出現(xiàn)的情況做到有備無患?！　?7. During the eighteenth century, Little Turtle was chief of the Miami tribe whose territory became what is now Indiana and Ohio.，“小烏龜”是邁阿密部落的酋長，該部落的地盤就是今天的印第安那州和俄亥俄州?！　?5. The history of painting is a fascinating chain of events that probably began with the very first pictures ever made.，其源頭大概可以上溯到最早的圖畫?！　?3. Probably no man had more effect on the daily lives of most people in the Untied States than did Henry Ford a pioneer in automobile production.。 51. Using many symbols makes it possible to put a large amount of inFORMation on a single map.?！　?9. Children with parents whose guidance is firm, consistent, and rational are inclined to possess high levels of selfconfidence.，始終如一和理性，孩子就有可能充滿自信?！　?7. Not until 1866 was the fully successful transatlantic cable finally laid.?！　?5. Quails typically have short rounded wings that enable them to spring into full flight instantly when disturbed in their hiding places.，憑此他們可以在受驚時(shí)一躍而起，飛離它們的躲藏地?！　?3. It is the interaction between people, rather than the events that occur in their lives, that is the main focus of social psychology.，而不是他們各自生活中的事件?！　?1. The annual worth of Utah’s manufacturing is greater than that of its mining and farming bined.?！　?9. The continental divide refers to an imaginary line in the North American Rockies that divides the waters flowing into the Atlantic Ocean from those flowing into the Pacific.，該線把大西洋流域和太平洋流域區(qū)分開來?！　?7. Lucretia Mott’s influence was so significant that she has been credited by some authorities as the originator of feminism in the United States.37. Lucretia Mott’s的影響巨大，所以一些權(quán)威部門認(rèn)定她為美國女權(quán)運(yùn)動(dòng)的創(chuàng)始人。拒絕一切傳統(tǒng)，試圖通過強(qiáng)調(diào)機(jī)械和動(dòng)態(tài)來美化生活?！　?4. The elimination of inflation would ensure that the amount of money used in repaying a loan would have the same value as the amount of money borrowed.?！　?2. That xenon could not FORM chemical pounds was once believed by scientists.：氙氣是不能形成化合物的。　　30. Because its leaves remain green long after being picked, rosemary became associated with the idea of remembrance.，因此人們把迷迭香樹與懷念聯(lián)系在一起?！　?8. Elizabeth Blackwell, the first woman medical doctor in the United States, founded the New York Infirmary, an institution that has always had a pletely female medical staff.28. Elizabeth Blackwell，美國第一個(gè)女醫(yī)生，創(chuàng)建了員工一直為女性紐約診所?！　?6. By the middle of the twentieth century, painters and sculptors in the United States had begun to exert a great worldwide influence over art.，美國畫家和雕塑家開始在世界范圍內(nèi)對(duì)藝術(shù)產(chǎn)生重大影響?！　?4. Most substance contract when they freez