What proportion of Americans live in areas with poor air quality?

Correct Answer: B

Rationale: The correct answer is B (50%). This is because empirical data shows that around half of Americans live in areas with poor air quality due to factors like pollution, industrial activities, and traffic congestion. Choice A (10%) is too low and underestimates the prevalence of poor air quality in the US. Choice C (75%) is too high and exaggerates the problem, as not three-quarters of Americans are affected. Choice D (90%) is also an overestimation, as the majority but not almost all Americans are impacted by poor air quality. Therefore, B is the most accurate representation of the proportion of Americans living in areas with poor air quality.

Correct Answer: B

Rationale: The correct answer is B because air pollutants like sulfur dioxide and nitrogen oxides can mix with moisture in the air to form acidic compounds. When these acidic compounds dissolve in rainwater or dew, they can damage forests and buildings by causing corrosion, deterioration of materials, and harming plant life. Particulates (choices A and C) can physically damage surfaces but do not directly cause the chemical reactions that lead to harm. Dehydration of surfaces (choice D) is not a significant mechanism for the harm caused by air pollution to forests and buildings.

Correct Answer: D

Rationale: The correct answer is D because systematically treating animals with antibiotics can lead to the selection of pathogenic organisms that develop resistance to the drugs. This occurs due to the survival and proliferation of resistant strains when exposed to antibiotics, posing a significant threat to human health by potentially transferring these resistant genes to humans through food consumption. Choices A, B, and C are incorrect as raising the cost of meat, making animals sick, and developing resistance to drugs are not the primary concern associated with the misuse of antibiotics in animal agriculture.

Correct Answer: A

Rationale: The correct answer is A because nausea, vomiting, abdominal cramps, fever, and diarrhea are common symptoms of bacterial infections. B is incorrect as it refers to intoxication rather than infection. C is incorrect as encysted larvae are not indicative of bacterial infections. D is incorrect as brain inclusions are not typically associated with bacterial infections. In summary, the symptoms listed in choice A align with typical manifestations of bacterial infections, making it the correct answer.

Correct Answer: D

Rationale: The correct answer is D, "All of the above." Medical waste can contain infectious agents like bacteria and viruses, toxic chemicals like chemotherapy drugs or disinfectants, and sources of radiation such as used radioactive materials. It is important to handle medical waste carefully to prevent exposure to these hazardous materials. Choices A, B, and C are incorrect individually as they only represent a part of the hazardous materials present in medical waste. The correct answer encompasses all potential hazards found in medical waste, making it the most comprehensive and accurate choice.