Question: I read this background article the other day: As for the public health or food safety concern, organic foods are intended to be healthy, free of contaminations and free from agents that could cause human diseases. Organic milk is meant to have no chemical residues to consumers, and the restrictions on the use of antibiotics and chemicals in organic food production has the purpose to accomplish this goal. Although dairy cows in both organic and conventional farming practices can be exposed to pathogens, it has been shown that, because antibiotics are not permitted as a preventative measure in organic practices, there are far fewer antibiotic resistant pathogens on organic farms. This dramatically increases the efficacy of antibiotics when/if they are necessary.  I am facing a new situation today: Two farmers sold their produce and milk on a large nearby market. John practiced organic farming and also produced organic milk, while Danny sold non-organic produce and milk.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which farmer sold more foods free of contaminations?
Answer: John

Question: I read this background article the other day: Middle adulthood lasts from the mid-30s to the mid-60s. During this stage of life, many people raise a family and strive to attain career goals. They start showing physical signs of aging, such as wrinkles and gray hair. Typically, vision, strength and reaction time start declining. Diseases such as type 2 diabetes, cardiovascular or heart disease, and cancer are often diagnosed during this stage of life. These diseases are also the chief causes of death in middle adulthood.  I am facing a new situation today: Pat and Tammy are mother and sister. They like to take long walks together. Pat is 60, while Tammy is 32 years-old.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which person shows less gray hair?
Answer: Tammy

Question: I read this background article the other day: Greenhouse Effect: The solar energy reaching the surface of the Earth is concentrated in short wavelengths, which can easily penetrate the greenhouse gases, such as carbon dioxide and methane. The Earth, however, is cooler than the sun and it radiates its heat in the form of energy in the far infrared range. These longer wavelengths are partially absorbed by the greenhouse gases and some of the solar heat is returned to Earth. At a certain temperature these processes are in equilibrium and the surface temperature of the Earth is stable. However, if more greenhouse gases are put in the atmosphere the amount of trapped terrestrial radiation increases, leading to an increase in global temperature.  I am facing a new situation today: Two friends liked studying about the Earth's atmosphere. Vick studied more about the troposphere, while Frank studied more about the Greenhouse Effect.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which friend studied more about short wavelength solar energy?
Answer:
Frank