The financial firm Dow Jones and Company computes business statistics every hour on the hour of each of the business days of the year and these statistics are known as the Dow Jones averages. They are based on a select group of stocks and bonds that are traded on the New York Stock Exchange. The Dow Jones averages are composed of four different types of averages: the average price of the common stock of thirty industrial firms, the average price of the common stock prices of twenty transportation companies, the average price of the common stock prices of fifteen utility companies, and an overall average of all the sixty-five stocks used to compute the first three averages. Probably the average that is the most commonly used is the industrial average; it is often used by an investor interested in checking the state of the stock market before making an investment in an industrial stock.

The pronoun "it" in line 8 refers to.....

The La Brea tarpits, located in Hancock Park in the Los Angeles area, have proven to be an extremely fertile source of Ice Age fossils. Apparently, during the period of the Ice Age, the tarpits were covered by shallow pools of water; when animals came there to drink, they got caught in the sticky tar and perished. The tar not only trapped the animals, leading to their death, but also served as a remarkably effective preservant, allowing near-perfect skeletons to remain hidden until the present era.

In 1906, the remains of a huge prehistoric bear discovered in the tarpits alerted archeologists to the potential treasure lying within the ta1~ Since then thousands and thousands of well-preserved skeletons have been uncovered, including the skeletons of camels, horses, wolves, tigers, sloths, and dinosaurs.

The pronoun "they" in line 3 refers to....

The life span of an elephant that dies from natural causes is about sixty-five years. Of course, an elephant can perish from a number of "unnatural causes"; e.g., it can be killed by hunters, most probably for the valuable ivory in its tusks; it can die from diseases that spread throughout an elephant herd; or it can die from drought or from the lack of food that almost certainly accompanies the inadequate supply of water.

If, however an elephant survives these disasters, it falls prey to old age in its mid-sixties. Around this age, the cause of death is attributed to the loss of the final set of molars. When this last set of teeth is gone, the elephant dies from malnutrition because it is unable to obtain adequate nourishment. In old age, elephants tend to search out a final home where there is shade for comfort from the sun and soft vegetation for cushioning; the bones of many old elephants have been found in such places.

The word "unnatural" in line 2 is closest in meaning to....

The life span of an elephant that dies from natural causes is about sixty-five years. Of course, an elephant can perish from a number of "unnatural causes"; e.g., it can be killed by hunters, most probably for the valuable ivory in its tusks; it can die from diseases that spread throughout an elephant herd; or it can die from drought or from the lack of food that almost certainly accompanies the inadequate supply of water.

If, however an elephant survives these disasters, it falls prey to old age in its mid-sixties. Around this age, the cause of death is attributed to the loss of the final set of molars. When this last set of teeth is gone, the elephant dies from malnutrition because it is unable to obtain adequate nourishment. In old age, elephants tend to search out a final home where there is shade for comfort from the sun and soft vegetation for cushioning; the bones of many old elephants have been found in such places.

The word "drought" in line 4 means....

Tornadoes occur throughout the world, but for reasons that scientists are not fully able to discern, the great majority occur in the United States. Approximately 700 tornadoes a year occur within the United States, and this comprises three-quarters of the worldwide total. Most of the U.S tornadoes take place in the Midwest and in the southern states that border the Gulf of Mexico.

In general a tornado cuts a path of a few hundred yards and lasts less than an hour; an average tornado might propel itself at a speed of 15 or 20 miles per hour and therefore cover a distance of 20 or so miles. Tornadoes, however, can be much worse than average. The most devastating tornado on record occurred on March 18, 1925, in the states of Missouri, Illinois, and Indiana. The path of this tornado was more than 200 miles long and a mile wide. Traveling at an average speed of 60 miles per hour, the winds at the center of the storm swirled around at considerably more than 200 miles per hour. A total of 689 people died, and countless more were injured at the hands of this killer storm.

The word "discern" in line 2 is closest in meaning to which of the following?

Tornadoes occur throughout the world, but for reasons that scientists are not fully able to discern, the great majority occur in the United States. Approximately 700 tornadoes a year occur within the United States, and this comprises three-quarters of the worldwide total. Most of the U.S tornadoes take place in the Midwest and in the southern states that border the Gulf of Mexico.

In general a tornado cuts a path of a few hundred yards and lasts less than an hour; an average tornado might propel itself at a speed of 15 or 20 miles per hour and therefore cover a distance of 20 or so miles. Tornadoes, however, can be much worse than average. The most devastating tornado on record occurred on March 18, 1925, in the states of Missouri, Illinois, and Indiana. The path of this tornado was more than 200 miles long and a mile wide. Traveling at an average speed of 60 miles per hour, the winds at the center of the storm swirled around at considerably more than 200 miles per hour. A total of 689 people died, and countless more were injured at the hands of this killer storm.

The word "propel" in line 6 could best be replaced by.....

Although the Wealth of Nations by Adam Smith appeared in 1776, it includes many of the ideas that economists still consider the foundation of private enterprise. The ideas put forth by Smith compose the basis of the philosophies of the school of thought called classical economics.

According to Smith's ideas, free competition and free trade are vital in fostering the growth of an economy. The role of government in the economy is to ensure the ability of companies to compete freely.

Smith, who was himself a Scot, lived during the period of the revolutions in America and in France. During this epoch, the predominant political thought was a strong belief in freedom and independence in government. Smith's economic ideas of free trade and competition are right in line with these political ideas.

A "school" in line 3 is ...

Although the Wealth of Nations by Adam Smith appeared in 1776, it includes many of the ideas that economists still consider the foundation of private enterprise. The ideas put forth by Smith compose the basis of the philosophies of the school of thought called classical economics.

According to Smith's ideas, free competition and free trade are vital in fostering the growth of an economy. The role of government in the economy is to ensure the ability of companies to compete freely.

Smith, who was himself a Scot, lived during the period of the revolutions in America and in France. During this epoch, the predominant political thought was a strong belief in freedom and independence in government. Smith's economic ideas of free trade and competition are right in line with these political ideas.

The word "line" in line 9 could best be replaced by...

It is common practice to coat metals such as iron and steel with a protective layer of zinc or an alloy made from zinc mixed with aluminum, cadmium, or tin in a process known as "galvanization." The purpose of galvanization is to prevent the corrosion of the iron or steel.

The most common method to galvanize metal is the hot-dip galvanizing process. In this process, the iron or steel is dipped into a hot bath of a zinc alloy to form a protective coating approximately .003 inches thick. Another method of galvanizing that is not as common is the process known as electrogalvanizing; in this process the metal is placed in a solution composed of zinc sulphate and water and is then charged electrically. This causes a thin layer of zinc to coat the metal.

Zinc is effective in galvanizing metals such as iron or steel in that zinc reacts more easily with oxygen than iron does. If iron is unprotected, it reacts with the oxygen in the air to form iron oxide, or rust, which leads to the corrosion of the iron. If, however, the iron is coated with zinc, as it is in the galvanization process, then it is the zinc rather than the iron which interacts with the oxygen to form zinc oxide, and the iron is not subject to corrosion.

Where in the passage does the author list the components of a zinc alloy?

It is common practice to coat metals such as iron and steel with a protective layer of zinc or an alloy made from zinc mixed with aluminum, cadmium, or tin in a process known as "galvanization." The purpose of galvanization is to prevent the corrosion of the iron or steel.

The most common method to galvanize metal is the hot-dip galvanizing process. In this process, the iron or steel is dipped into a hot bath of a zinc alloy to form a protective coating approximately .003 inches thick. Another method of galvanizing that is not as common is the process known as electrogalvanizing; in this process the metal is placed in a solution composed of zinc sulphate and water and is then charged electrically. This causes a thin layer of zinc to coat the metal.

Zinc is effective in galvanizing metals such as iron or steel in that zinc reacts more easily with oxygen than iron does. If iron is unprotected, it reacts with the oxygen in the air to form iron oxide, or rust, which leads to the corrosion of the iron. If, however, the iron is coated with zinc, as it is in the galvanization process, then it is the zinc rather than the iron which interacts with the oxygen to form zinc oxide, and the iron is not subject to corrosion.

Where in the passage docs the author describe what happens when iron and oxygen interact?