Background: Human beings invented agriculture about 10,000 years ago. This provided a bigger, more dependable food supply. It also allowed people to settle down in villages and cities for the first time. Birth rates went up because there was more food and settled life had other advantages. Death rates also rose because of crowded living conditions and diseases that spread from domestic animals. Because the higher birth rates were matched by higher death rates, the human population continued to grow very slowly. Paragraph: David was studying human history. He selected two specific eras of human history, era A and era B. Era A was before humans had invented agriculture. And, era B was after the invention of agriculture. He noticed that human societies had changed dramatically after the invention of agriculture. Given the paragraph above, please answer correctly the following question: Which era saw higher birth rate, era A or era B?
----
Answer: era B

Background: Making these healthy lifestyle choices can also help prevent some types of cancer. In addition, you can lower the risk of cancer by avoiding carcinogens , which are substances that cause cancer. For example, you can reduce your risk of lung cancer by not smoking. You can reduce your risk of skin cancer by using sunscreen. How to choose a sunscreen that offers the most protection is explained below ( Figure below ). Some people think that tanning beds are a safe way to get a tan. This is a myth. Tanning beds expose the skin to UV radiation. Any exposure to UV radiation increases the risk of skin cancer. It doesn't matter whether the radiation comes from tanning lamps or the sun. Paragraph: Danny and Bill both read about lifestyle choices and how these influence the risk of getting cancer. Danny made drastic healthier lifestyle choices, while Bill moved on and continued with his fast-food died , tanning saloons and smoking tobacco. Given the paragraph above, please answer correctly the following question: Which person didn't start using sunscreen?
----
Answer: Bill

Background: Compared to conventional milk production, organic milk production tends to have lower eutrophication potential per ton of milk or per hectare of farmland, because it potentially reduces leaching of nitrates (NO3) and phosphates (PO4) due to lower fertilizer application rates. Because organic milk production reduces pesticides utilization, it increases land use per ton of milk due to decreased crop yields per hectare. Mainly due to the lower level of concentrates given to cows in organic herds, organic dairy farms generally produce less milk per cow than conventional dairy farms. Because of the increased use of roughage and the, on-average, lower milk production level per cow, some research has connected organic milk production with increases in the emission of methane.Animal welfare issues vary among dairy farms and are not necessarily related to the way of producing milk (organically or conventionally). Paragraph: Peet farm was supplying a nearby city with organic milk. Toad farm was a competitor on the same market, but they didn't produce organic milk, they used conventional agricultural methods. Given the paragraph above, please answer correctly the following question: Which farm leached fewer nitrates (NO3)?
----
Answer:
Peet