Read the following passage about What Each Generation Refuses to Learn from the Last and mark the letter A, B, C or D on your answer sheet t...

Read the following passage about What Each Generation Refuses to Learn from the Last and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 28 to 35.

Many people enjoy diets that are rich in meat and dairy products. But experts warn that we cannot continue in this trend for long. The current demand for food products that come from animals is not sustainable, and future generations are going to have to change their eating habits.

One major reason why this trend is unsustainable is the amount of water required. It takes a lot more water to feed animals than it does to grow grains. For example, fifteen cubic meters of water is needed to produce a kilogram of beef, whereas a kilo of cereals needs less than three cubic meters. It also takes more water to process the meat and to refrigerate it. The meat industry consumes over half of all water used for all purposes in the United States, and most of this water is used to irrigate cattle feedlots.

Not only does meat production use up a lot of water, it also causes water pollution and affects land. Waste from livestock contains high levels of nitrogen and phosphorus. These chemicals pollute the groundwater and waterways. The percentage of U.S. agricultural land used to produce meat is 56%. The strains on land include topsoil erosion and depletion of forested areas.

This industry is also subsidized by the government. Therefore, the price paid for meat doesn’t reflect the environmental hazards involved in the process. As a result, most people are unaware of the negative impact the production of meat has on the environment, as well as how much it depletes the resources so badly needed for the future. Because it is not reflected in the cost, many people remain unaware of these facts. Furthermore, many producers tend to ignore these facts in order to continue making a profit.

(Adapted from Mastering skills for TOEFL iBT)

Question 28. Which of the following is NOT mentioned as a negative effect of meat production?

A. air pollution                                        B. forest loss

C. topsoil erosion                                        D. water contamination