Because of a recent drought in Florida during the orange-growing season

Because of a recent drought in Florida during the orange-growing season, the price of oranges this season will be three times the usual price. This will drive up the cost of producing orange juice and thus push up the price of orange juice for the consumer.
Which of the following, if true, most seriously weakens the argument above?

1. The recent drought was not as severe as scientists predicted.
2. States other than Florida also supply oranges to orange juice manufacturers.
3. Other ingredients are used in the production of orange juice.
4. Last year the price of oranges was actually lower than the average price over the past ten years.
5. The price of oranges will eventually be $0.48 per crate.

Since the passage of the state’s Clean Air Act ten years ago

Since the passage of the state’s Clean Air Act ten years ago, the level of industrial pollutants in the air has fallen by an average of 18 percent. This suggests that the restrictions on industry embodied in the act have worked effectively. However, during the same period the state has also suffered through a period of economic decline. The number of businesses in the state has fallen by 10 percent, and the number of workers employed has fallen by 12 percent. It is probable that the business decline, rather than the regulations in the act, is responsible for at least half of the decline in the pollution.

Which of the following, if true, would most seriously weaken the conclusion drawn in the passage above?

1. During the last ten years, economic conditions in the nation as a whole have been worse than those within the state.
2. Amendments to the Clean Air Act that were enacted six years ago have substantially strengthened its restrictions on industrial air pollution.
3. Of the businesses that ceased operating in the state during the last ten years, only 5 percent were engaged in air-polluting industries.
4. Several large corporations left the state during the last ten years partly in order to avoid compliance with the Clean Air Act.
5. Due to its small budget, the state office charged with enforcement of the Clean Air Act has prosecuted only two violators of the law since its passage.

The postal service is badly mismanaged.

The postal service is badly mismanaged. Forty years ago, first-class letter delivery cost only three cents. Since then, the price has increased nearly tenfold, with an actual decrease in the speed and reliability of service.

Each of the following statements, if true, would tend to weaken the argument above EXCEPT:

a. The volume of mail handled by the postal service has increased dramatically over the last forty years.

b. Unprecedented increases in the cost of fuel for trucks and planes have put severe upward pressures on postal delivery costs.

c. Private delivery services usually charge more than does the postal service for comparable delivery charges.

d. The average delivery time for a first-class letter four decades ago was actually slightly longer than it is today.（E）

e. The average level of consumer prices overall has increased more than 300 percent over the last forty years.