Question: I read this background article the other day: Gasoline-powered vehicles emit a lot of harmful materials. Nitrogen oxides are formed when atmospheric nitrogen reacts with oxygen at the high temperatures found in a car engine. Carbon monoxide is a by-product of incomplete combustion of hydrocarbons. Evaporated and unused fuel releases volatile hydrocarbons into the atmosphere to help form smog. The presence of a catalytic converter in the exhaust system of the car causes these materials to react and be changed into less harmful products. I am facing a new situation today: Blue island and Red island were two big sister islands situated 100 miles from each other. People on Blue island used gas powered vehicles, while people on Red island used electrical vehicles. The people on Blue island presented more respiratory problems. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which island released more nitrogen oxides into the atmosphere?
Answer: Blue

Question: I read this background article the other day: Depleted soils can be protected from soil erosion by groundcover plants such as naturally growing grasses in agroforestry systems. These help to stabilise the soil as they increase cover compared to short-cycle cropping systems. Soil cover is a crucial factor in preventing erosion. Cleaner water through reduced nutrient and soil surface runoff can be a further advantage of agroforestry. The runoff can be reduced by decreasing its velocity and increasing infiltration into the soil. Compared to row-cropped fields nutrient uptake can be higher and reduce nutrient loss into streams.Further advantages concerning plant growth: I am facing a new situation today: Rob is an environmental scientist. He was doing a study on agroforestry. To test the sustainability of agroforestry he conducted two pilot projects, pilot A and pilot B. In pilot A, he used a land for agrofroestry. In pilot B, he used a land for usual row-cropping. He needed to find the pros and cons of both systems. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which project would have more soil cover, pilot A or pilot B?
Answer: pilot A

Question: I read this background article the other day: Air pollution can also indirectly cause other health issues and even deaths. Air pollutants can cause an increase in cancer including lung cancer, eye problems, and other conditions. For example, using certain chemicals on farms, such as the insecticide DDT (dichlorodiphenyltrichloroethane) and toxic PCBs (polychlorinated biphenyl), can cause cancer. Indoors, pollutants such as radon or asbestos can also increase your cancer risk. Lastly, air pollution can lead to heart disease, including heart attack and stroke. I am facing a new situation today: The health inspectors reviewed data from two villages, Key and Auburn. Key village presented higher levels of both indoor and outdoor pollution. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which village had a lower level of air pollutants?
Answer:
Auburn