1.A drug that is highly effective in treating many types of infection can, at present, be obtained only from the bark of the ibora, a tree that is quite rare in the wild. It takes the bark of 5,000 trees to make one kilogram of the drug. It follows, therefore, that continued production of the drug must inevitably lead to the ibora's extinction.Which of the following, if true, most seriously weakens the argument above?

　　（A） The drug made from ibora bark is dispensed to doctors from a central authority.
　　（B） The drug made from ibora bark is expensive to produce.
　　（C） The leaves of the ibora are used in a number of medical products.
　　（D） The ibora can be propagated from cuttings and grown under cultivation.
　　（E） The ibora generally grows in largely inaccessible places.

　　2.High levels of fertilizer and pesticides, needed when farmers try to produce high yield of the same crop year after year, pollute water supplies. Experts therefore urge farmers to diversify their crops and to rotate their plantings yearly.To receive governmental price-support benefits for a crop, farmers must have produced that same crop for the past several years.The statements above, if true, best support which of the following conclusions?

　　（A） The rules for governmental support of farm prices work against efforts to reduce water pollution.
　　（B） The only solution to the problem of water pollution from fertilizers and pesticides is to take farmland out of production.
　　（C） Farmers can continue to make a profit by rotating diverse crops, thus reducing costs for chemicals, but not by planting the same crop each year.
　　（D） New farming techniques will be developed to make it possible for farmers to reduce the application of fertilizers and pesticides.
　　（E） Governmental price supports for farm products are set at levels that are not high enough to allow farmers to get out of debt.

　　3.Shelby Industries manufactures and sells the same gauges as Jones Industries. Employee wages account for forty percent of the cost of manufacturing gauges at both Shelby Industries and Jones Industries. Shelby Industries is seeking a competitive advantage over Jones Industries. Therefore, to promote this end, Shelby Industries should lower employee wages.Which of the following, if true, would most weaken the argument above?

　　（A） Because they make a small number of precision instruments, gauge manufacturers cannot receive volume discounts on raw materials.
　　（B） Lowering wages would reduce the quality of employee work, and this reduced quality would lead to lowered sales.
　　（C） Jones Industries has taken away twenty percent of Shelby Industries' business over the last year.
　　（D） Shelby Industries pays its employees, on average, ten percent more than does Jones Industries.
　　（E） Many people who work for manufacturing plants live in areas in which the manufacturing plant they work for is the only industry.

　　4.Some communities in Florida are populated almost exclusively by retired people and contain few, if any, families with small children. Yet these communities are home to thriving businesses specializing in the rental of furniture for infants and small children.Which of the following, if true, best reconciles the seeming discrepancy described above?

　　（A） The businesses specializing in the rental of children's furniture buy their furniture from distributors outside of Florida.
　　（B） The few children who do reside in these communities all know each other and often make overnight visits to one another's houses.
　　（C） Many residents of these communities who move frequently prefer renting their furniture to buying it outright.
　　（D） Many residents of these communities must provide for the needs of visiting grandchildren several weeks a year.
　　（E） Children's furniture available for rental is of the same quality as that available for sale in the stores.

　　5.Large national budget deficits do not cause large trade deficits. If they did, countries with the largest budget deficits would also have the largest trade deficits. In fact, when deficit figures are adjusted so that different countries are reliably comparable to each other, there is no such correlation.If the statements above are all true, which of the following can properly be inferred on the basis of them?

　　（A） Countries with large national budget deficits tend to restrict foreign trade.
　　（B） Reliable comparisons of the deficit figures of one country with those of another are impossible.
　　（C） Reducing a country's national budget deficit will not necessarily result in a lowering of any trade deficit that country may have.
　　（D） When countries are ordered from largest to smallest in terms of population, the smallest countries generally have the smallest budget and trade deficits.
　　（E） Countries with the largest trade deficits never have similarly large national budget deficits.