Passage 1 Directions: There are 20 blanks in the following passage. For each blank there are four choices marked A, B, C and D. Choose the best answer for each blank . There is probably no sound in 1 more chilling than the " hiss " of a diamondback rattlesnake. There is good reason: the western diamondback has killed more humans than 2 snake. It is easily excitable, very aggressive, frequently hungry, and deadly poisonous. Yet it doesn't really hiss. Rather, it 3 its tail. A mature rattler can move its tail up and down between fifty and a hundred times a second! The hollow rattles 4 the tail, beating against each other, create the "hissing" sound. Why does this creature 5 rattles? Rattlesnakes molt three times a year, shedding their outer layer of skin each time. But the molting skin near the tail is not discarded. 6 it hardens and hollows out, becoming another rattle. If a snake had never lost any rattles, you could 7 its age by counting them and dividing by three. Do the snakes need their rattles? The rattles cannot be used in a mating call, 8 rattlesnakes are deaf. They are not a sign of hunger, for snakes with full stomachs rattle as often as hungry 9 . And in the wild, the rattling scares prey. It does not 10 them. Therefore, scientists believe that snakes use rattles merely to warn larger animals not to step on 11 . They have studied them extensively and found that it was a function more important in ages past when the rattlers shared the plains 12 60 million buffalo! Rattlesnakes are one of the 13 advanced forms of " pit " vipers—animals who possess an organ for an extra sense. The pit organ is like an infrared radar sensor. 14 in the snake's head, the pit organ can sense differences in temperature between inside and outside itself—differences as small as 1% of a degree. Not only can rattlesnakes 15 sense the presence of another animal—or a human—but they apparently can 16 determine its direction and range. These animals don't feed on 17 , of course. Their poison, however, may kill humans. But this happens only in 18 they think is self-defense. Rattlesnakes are really quite 19 Their principal diet of mice and rats makes them valuable to the ecology of the West. So rather than fear them, we should respect the 20 they play in containing the population of these harmful pests.
Passage 2 Directions: There are 20 blanks in the following passage. For each blank there are four choices marked A, B, C and D. Choose the best answer for each blank . Sulphur is one of the oldest, cheapest, and most useful minerals in the world. Yellowish or greenish in 1 , this odorless material is found in the earth in a crystal form. We have discovered thousands of 2 for it. For this reason, every man, woman, and child in America 3 about seventy-five pounds of it each year. Until 1900 almost all of the world's supply of sulphur came from the Italian 4 of Sicily. Since then America has discovered how to mine its own vast supplies found in Texas and Louisiana. Spain, Mexico, and South America are also 5 for it. 6 , we know there are trillions of tons of sulphur in our oceans. In Sicily sulphur was found near the earth's surface, but American miners had to learn 7 to extract sulphur from 1200 to 1500 feet underground. There were many years of experiments. Then they finally found the 8 . Several pipes were drilled down to the sulphur deposits. Some of them carried boiling water, causing the sulphur to 9 . Then other pipes carried the mineral up and 10 of the earth in a liquid form. Most people do not realize that the manufacture of many common articles 11 on sulphur. Some farmers use compounds of this mineral to 12 insects and plant pests. It is an important ingredient in the manufacture of paper pulp, 13 is used for our books and magazines. Researchers have found that some forms of sulphur can be used in fighting infections. Therefore many 14 include this mineral. Gunpowder, camera and X-ray film, and mbber tires also 15 sulphur. About eighty percent of all the sulphur 16 goes into the manufacture of sulphurie acid. In its pure form it has no 17 . However, sulphide compounds 18 have the strong smell of rotten eggs. Although most sulphurie acid is used to make fertilizers and to refine petroleum, it is an ingredient in hundreds of other commodities 19 , from textiles to glue, food preservatives, paint, and 20 glass.
Passage 3 Directions: There are 20 blanks in the following passage. For each blank there are four choices marked A, B, C and D. Choose the best answer for each blank . This large city does almost no manufacturing and very little wholesale trade. Yet without the important service 1 provides, business everywhere would quickly grind to a 2 . Chaos would reign in all other leading cities. As you have guessed, the "product" we are talking about is government, and the city is the 3 of the United States, Washington, D. C. One out of every two persons 4 in the city works for the federal government. Washington has many 5 . It leads the nation in level of education achieved by its residents. More than fifteen percent of its adults have had four years or more of college. 6 scientists can be found here than in any other city. Since larger incomes are earned by 7 people, Washington has the highest median income of any city. Information is the vital force of the city. The Library of Congress 8 the largest and most comprehensive warehouse of information in the world. It contains 74 million items on hundreds of miles of 9 . In addition to books, these 10 include manuscripts, maps, photographs and documents. Papers of the Presidents all the way back to Washington are found here. The library is 11 to the public. It is considered by 12 to be one of the finest in the world. These people study the documents found in libraries. Washington has many important governmental buildings and historic shrines. 13 include the Capitol building, the White House, the Supreme Court, the Lincoln Memorial, and the Washington Monument. The Bureau of Engraving and Printing is 14 located here. This agency is responsible 15 putting new paper money into circulation. Tens of millions of dollars in money is 16 here every day. Unlike most cities, which grow in jumbled masses, Washington was planned on paper 17 any of its buildings were erected. The planners incorporated broad open areas around the historic landmarks and buildings. As a result the city is 18 . The central part of the city 19 a huge green park with broad, tree-lined boulevards and splendid 20 of its great structures.
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