1.Typical of the grassland dwellers of the continent is the American antelope， or pronghorn.
2.Of the millions who saw Haley's comet in 1986， how many people will live long enough to see it return in the twenty-first century.
3.Anthropologists have discovered that fear， happiness， sadness， and surprise are universally reflected in facial expressions.
4.Because of its irritating effect on humans， the use of phenol as a general antiseptic has been largely discontinued.
5.In group to remain in existence， a profit-making organization must， in the long run， produce something consumers consider useful or desirable.
6.The greater the population there is in a locality， the greater the need there is for water， transportation， and disposal of refuse.
7.It is more difficult to write simply， directly， and effectively than to employ flowery but vague expressions that only obscure one's meaning.
8.With modern offices becoming more mechanized， designers are attempting to personalize them with warmer， less severe interiors.
9.The difference between libel and slander is that libel is printed while slander is spoken.
10.The knee is the joints where the thigh bone meets the large bone of the lower leg.
11.Acids are chemical compounds that， in water solution， have a sharp taste， a corrosive action onMETAls， and the ability to turn certain blue vegetable dyes red.
12.Billie Holiday's reputation as a great jazz-blues singer rests on her ability to give emotional depth to her songs.
13.Essentially， a theory is an abstract， symbolic representation of what is conceived to be reality.
14.Long before children are able to speak or understand a language， they communicate through facial expressions and by making noises.
15.Thanks to modern irrigation， crops now grow abundantly in areas where once nothing but cacti and sagebrush could live.
16.The development of mechanical timepieces spurred the search for more accurate sundials with which to regulate them.
17.Anthropology is a science in that anthropologists use a rigorous set of methods and techniques to文档observations that can be checked by others.
18.Fungi are important in the process of decay， which returns ingredients to the soil， enhances soil fertility， and decomposes animal debris.
19.When it is struck， a tuning fork produces an almost pure tone， retaining its pitch over a long period of time.
20.Although pecans are most plentiful in the southeastern part of the United States， they are found as far north as Ohio and Illinois.
21.Eliminating problems by transferring the blame to others is often called scape-goating.
22.The chief foods eaten in any country depend largely on what grows best in its climate and soil.
23.Over a very large number of trials， the probability of an event's occurring is equal to the probability that it will not occur.
24.Most substance contract when they freeze so that the density of a substance's solid is higher than the density of its liquid.
25.The mechanism by which brain cells store memories is not clearly understood.
26.By the middle of the twentieth century， painters and sculptors in the United States had begun to exert a great worldwide influence over art.
27.In the eastern part of New Jersey lies the city of Elizabeth， a major shipping and manufacturing center.
28.Elizabeth Blackwell， the first woman medical doctor in the United States， founded the New York Infirmary， an institution that has always had a completely female medical staff.
29.Alexander Graham Bell once told his family that he would rather be remembered as a teacher of the 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.
31.Although apparently rigid， bones exhibit a degree of elasticity that enables the skeleton to withstand considerable impact.
32.That xenon could not FORM chemical compounds was once believed by scientists.
33.Research into the dynamics of storms is directed toward improving the ability to predict these events and thus to minimize damage and avoid loss of life.
34.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.
35.Futurism， an early twentieth-century movement in art， rejected all traditions and attempted to glorify contemporary life by emphasizing the machine and motion.
36.One of the wildest and most inaccessible parts of the United States is the Everglades where wildlife is abundant and largely protected.
37.Lucretia Mott's influence was so significant that she has been credited by some authorities as the originator of feminism in the United States.
38.The activities of the international marketing researcher are frequently much broader than those of the domestic marketer.
39.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.
40.Studies of the gravity field of the Earth indicate that its crust and mantle yield when unusual weight is placed on them.