Problem: I have a new situation: The ecologist moved from Aspen, where there was no air pollution, to Seattle which experienced a lot of air pollution. He started studying the weather there as well. But I can use this background: One result of air pollution is acid rain. Acid rain is precipitation with a low (acidic) pH. This rain can be very destructive to wildlife. When acid rain falls in forests, freshwater habitats, or soils, it can kill insects and aquatic life. It causes this damage because of its very low pH. Sulfur oxides and nitrogen oxides in the air both cause acid rain to form ( Figure below ). Sulfur oxides are chemicals that are released from coal-fired power plants. Nitrogen oxides are released from motor vehicle exhaust. What is an answer for this question: Which city had more conditions for developing acid rain?

A: Seattle

Problem: I have a new situation: Two friends met after 20 years. Tom had been smoking tobacco all these years and had some health problems related to that, while Randy quit smoking 25 years ago. But I can use this background: Many different chemical substances cause cancer. Dozens of chemicals in tobacco smoke, including nicotine, have been shown to cause cancer ( Figure below ). In fact, tobacco smoke is one of the main sources of chemical carcinogens. Smoking tobacco increases the risk of cancer of the lung, mouth, throat, and bladder. Using smokeless tobacco can also cause cancer. Other chemicals that cause cancer include asbestos, formaldehyde, benzene, cadmium, and nickel. What is an answer for this question: Which friend was at a lower risk for developing cancer?

A: Randy

Problem: I have a new situation: Town A disposed of the biomedical waste from their hospital conventionally in a regular dump site for 10 years because it was more convenient, while town B took them to an ecological site where they wouldn't affect ground water and spread disease. But I can use this background: One of the most adverse impacts of poor waste management, especially municipal waste, is the incidence and prevalence of diseases such as malaria and respiratory problems, as well as other illnesses through the contamination of ground water. Biomedical wastes pose great danger in Bangladesh too as a report estimated that 20% of the biomedical waste is "highly infectious" and is a hazard since it is often disposed of into the sewage system or drains.[6] Such poor sanitation has serious consequences for the health of the residents and a report suggests that "most of the child mortality could be related with this problem".[7] With regards to the living standards, solid waste leads to blockage in the drainage system which leads to flooding in the streets. Consequently, mosquitoes and bad odour are among the negative impacts resulted.[7] What is an answer for this question: Which town is experiencing fewer mosquitoes?

A: town B

Problem: I have a new situation: Jacob recently contracted the HIV virus and is going to his first support meeting. While there, he meets Dan and strikes up a conversation with him. Dan says that he has had HIV for over a decade at this point and has learned ways to live with it. He is able to give Jacob some good advice on how to handle things and Jacob is very grateful to have someone to talk with. But I can use this background: As time passes, the number of HIV copies keeps increasing, while the number of helper T cells keeps decreasing. The graph in Figure below shows how the number of T cells typically declines over a period of many years following the initial HIV infection. As the number of T cells decreases, so does the ability of the immune system to defend the body. As a result, an HIV-infected person develops frequent infections. Medicines can slow down the virus but not get rid of it, so there is no cure at present for HIV infections or AIDS. There also is no vaccine to immunize people against HIV infection, but scientists are working to develop one. What is an answer for this question: Is Dan's immune system weaker or stronger than Jacob's?

A:
weaker