【正文】 ng 10,000. D keeps the Moon in orbit around Earth and the plas other of the solar system in orbit A B C D around the Sun. 24. Photograph was revolutionized in 1831 by the introduction of the collodion process for making glass A B C D negatives. 25. After flax is washed, dry, beaten, and bed, fibers are obtained for use in making fabric. A B C D 26. A fever is caused which blood cells release proteins called pyrogens, raising the body’s temperature. A B C D 27. Because of various giftgiving holidays, most stores clothing in the United Sates do almost as much A B business in November and December as they do in the other ten months bined. C D United States National Labor Relations Board is authorized to investigation allegations of unfair A B labor practices on the part of either employers or employees. C D Great Potato Famine in Ireland in the 1840’s caused an unprecedented numbers of people from A B C 6 Ireland to immigrate to the United States. D particles prising a given cloud are continually changing, as new ones are added while others A B are taking away by moving air. C D parties in the United States help to coordinate the campaigns of their members and anizes A B C the statewide and national conventions that mark election years. D lemur is an unusual animal belonging to the same order than monkey’s and apes. A B C D may be hard or soft, depending on the amount of water left into it and the character of A B C D the cuting. carbonare lamp, a very bright electric lamp used for spotlights, consists of two carbon A B electrodes with a highcurrent are passing between it. C D 35. At first the poems of . Cummings gained notoriety to their idiosyncratic punctuation and A B typography, but they have gradually been recognized for their lyric power as well. C D mechanism of human thought and recall, a subject only partly understood by scientists, is A B C extraordinary plicated. D the process of photosynthesis in green plants, light energy is captured and used A B to convert water, carbon dioxide, and minerals into oxygen and anic pounds. C D globe artichoke was known as a delicacy at least 2,500 years ago, and records of its A B C cultivation date from fifteenth century. D 39. Humans do not constitute the only species endowed with intelligence: the higher animals also A B C have considerably problemsolving abilities. D 40. Many of species of milkweed are among the most dangerous of poisonous plants, while others A B C have little, if any, toxicity. D Section Three: Reading Comprehension Questions 110 In the early 1800’s, over 80 percent of the United States labor force was engaged in agriculture. Sophisticated technology and machinery were virtually nonexistent. People who lived in the cities and were not directly involved in trade often participated Line in small cottage industries making handcrafted goods. Others cured meats, silversmiths, candle 5) or otherwise produced needed goods and modities. Blacksmiths, silversmiths, candle makers, and other artisans worked in their homes or barns, relying on help of family Perhaps no single phenomenon brought more widespread and lasting change to the United States society than the rise of industrialization. Industrial growth hinged on several 7 10） economic factors. First, industry requires an abundance of natural resources, especially coal, iron ore, water, petroleum, and timberall readily available on the North American continent. Second, factories demand a large labor supply. Between the 1870’s and the First World War (19141918), approximately 23 million immigrants streamed to the United States, settled in cities, and went to work in factories and mines. They also helped 15） build the vast work of canals and railroads that crisscrossed the continent and linked important trade centers essential to industrial growth. Factories also offered a reprieve from the backbreaking work and financial unpredictability associated with farming. Many adults, poor and disillusioned with farm life, were lured to the cities by promises of steady employment, regular paychecks, 20) increased access to goods and services, and expanded social opportunities. Others were pushed there when new technologies made their labor cheap or expendable