6.     Which of the following best completes the passage below?Established companies concentrate on defending what they already have. Consequently, they tend not to be innovative themselves and tend to underestimate the effects of the innovations of others. The clearest example of this defensive strategy is the fact that______
(A) ballpoint pens and soft-tip markers have eliminated the traditional market for fountain pens, clearing the way for the marketing of fountain pens as luxury or prestige items
(B) a highly successful automobile was introduced by the same company that had earlier introduced a model that had been a dismal failure
(C) a once-successful manufacturer of slide rules reacted to the introduction of electronic calculators by trying to make better slide rules
(D) one of the first models of modern accounting machines, designed for use in the banking industry, was purchased by a public library as well as by banks
(E) the inventor of a commonly used anesthetic did not intend the product to be used by dentists, who currently account for almost the entire market for that drug

7.     Most archaeologists have held that people first reached the Americas less than 20,000 years ago by crossing a land bridge into North America. But recent discoveries of human shelters in South America dating from 32,000 years ago have led researchers to speculate that people arrived in South America first, after voyaging across the Pacific, and then spread northward.Which of the following, if it were discovered, would be pertinent evidence against the speculation above?
(A) A rock shelter near Pittsburgh, Pennsylvania, contains evidence of use by human beings 19,000 years ago.
(B) Some North American sites of human habitation predate any sites found in South America.
(C) The climate is warmer at the 32,000-year-old south American site than at the oldest known North American site.
(D) The site in South America that was occupied 32,000 years ago was continuously occupied until 6,000 years ago.
(E) The last Ice Age, between 11,500 and 20,000 years ago, considerably lowered worldwide sea levels.

8.     In Asia, where palm trees are non-native, the trees’ flowers have traditionally been pollinated by hand, which has kept palm fruit productivity unnaturally low. When weevils known to be efficient pollinators of palm flowers were introduced into Asia in 1980, palm fruit productivity increased—by up to fifty percent in some areas—but then decreased sharply in 1984.Which of the following statements, if true, would best explain the 1984 decrease in productivity?
(A) Prices for palm fruit fell between 1980 and 1984 following the rise in production and a concurrent fall in demand.
(B) Imported trees are often more productive than native trees because the imported ones have left behind their pests and diseases in their native lands.
(C) Rapid increases in productivity tend to deplete trees of nutrients needed for the development of the fruit-producing female flowers.
(D) The weevil population in Asia remained at approximately the same level between 1980 and 1984.
(E) Prior to 1980 another species of insect pollinated the Asian palm trees, but not as efficiently as the species of weevil that was introduced in 1980.

9.     Since the mayor’s publicity campaign for Greenville’s bus service began six months ago, morning automobile traffic into the midtown area of the city has decreased seven percent. During the same period, there has been an equivalent rise in the number of persons riding buses into the midtown area. Obviously, the mayor’s publicity campaign has convinced many people to leave their cars at home and ride the bus to work.Which of the following, if true, casts the most serious doubt on the conclusion drawn above?
(A) Fares for all bus routes in Greenville have risen an average of five percent during the past six months.
(B) The mayor of Greenville rides the bus to City Hall in the city’s midtown area.
(C) Road reconstruction has greatly reduced the number of lanes available to commuters in major streets leading to the midtown area during the past six months.
(D) The number of buses entering the midtown area of Greenville during the morning hours is exactly the same now as it was one year ago
(E) Surveys show that longtime bus riders are no more satisfied with the Greenville bus service than they were before the mayor’s publicity campaign began.

10.   In the aftermath of a worldwide stock-market crash, Country T claimed that the severity of the stock-market crash it experienced resulted from the accelerated process of denationalization many of its industries underwent shortly before the crash.Which of the following, if it could be carried out, would be most useful in an evaluation of Country T’s assessment of the causes of the severity of its stock-market crash?
(A) Calculating the average loss experienced by individual traders in Country T during the crash
(B) Using economic theory to predict the most likely date of the next crash in Country T
(C) Comparing the total number of shares sold during the worst days of the crash in Country T to the total number of shares sold in Country T just prior to the crash
(D) Comparing the severity of the crash in Country T to the severity of the crash in countries otherwise economically similar to Country T that have not experienced recent denationalization
(E) Comparing the long-term effects of the crash on the purchasing power of the currency of Country T to the immediate, more severe short-term effects of the crash on the purchasing power of the currency of Country T