Please answer correctly the following question related to the paragraph below. Which village burned fewer fossil fuels? When comparing village A from ten thousand years ago to village B from today, we reached the conclusion that today's villagers release much more carbon into the atmosphere by their activities. Hint: Because of human activities, there is more carbon dioxide in the atmosphere today than in the past hundreds of thousands of years. Burning fossil fuels and has released great quantities of carbon dioxide into the atmosphere. Cutting forests and clearing land has also increased carbon dioxide into the atmosphere because these activities reduce the number of autotrophic organisms that use up carbon dioxide in photosynthesis. In addition, clearing often involves burning, which releases carbon dioxide that was previously stored in autotrophs.
Ans: village A

Please answer correctly the following question related to the paragraph below. Which area is less likely to have acid rain? Beijing recently opened several new coal-fired power plants over the last few months. In Montreal, there have been large reductions in sulfur oxides produced by manufacturing plants after a recent referendum. Hint: 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.
Ans: Montreal

Please answer correctly the following question related to the paragraph below. Which farmer helped to stabilize the soil more? Gary and Joe are two farmers. Joe's farm has a depleted soil, while Gary started agroforestry a few years back, and grows cover crops. Hint: 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:
Ans: Gary

Please answer correctly the following question related to the paragraph below. Who will produce higher amounts of vitamin D? Robin and Samantha are both bodybuilders preparing for a competition. Both of them are trying to change their skin complexion to help their appearances at the competition. Robin begins exposing her skin to high amounts of UV light several days a week. Samantha decides not to use any UV light and instead just uses lotion to help her skin. Hint: The epidermis also contains melanocytes , which are cells that produce melanin. Melanin is the brownish pigment that gives skin much of its color. Everyone has about the same number of melanocytes, but the melanocytes of people with darker skin produce more melanin. The amount of melanin produced is determined by heredity and exposure to UV light, which increases melanin output. Exposure to UV light also stimulates the skin to produce vitamin D . Because melanin blocks UV light from penetrating the skin, people with darker skin may be at greater risk of vitamin D deficiency.
Ans: Robin