Please answer this: I read this background article the other day: Magnetism is the ability of a material to be attracted by a magnet and to act as a magnet. Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, it causes the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materials, the north and south poles of atoms point in all different directions, so overall the material is not magnetic. Examples of nonmagnetic materials include wood, glass, plastic, paper, copper, and aluminum. These materials are not attracted to magnets and cannot become magnets. I am facing a new situation today: Rob got a compass as a present for his birthday. The magnet in the compass made him very interested in how magnets work. To understand magnets better he categorized objects in two groups, group A and group B. In group A all objects were magnetic, but in group B none of the objects was magnetic. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which group's objets might not include paper or plastic, group A or group B?
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Answer: group A
Problem: I read this background article the other day: Rain dissolves fertilizer in the soil. Runoff carries it away. The fertilizer ends up in bodies of water, from ponds to oceans. Nitrogen is a fertilizer in the water. Since there is a lot of nitrogen, it causes algae to grow out of control. Pictured below is a pond covered with algae ( Figure below ). Algae use up carbon dioxide in the water. After the algae die, decomposers break down the dead tissue. The decomposers use up all the oxygen in the water. This creates a dead zone. A dead zone is an area in a body of water where nothing grows because there is too little oxygen. There is a large dead zone in the Gulf of Mexico ( Figure below ). The U.S. states outlined on the map have rivers that drain into the Gulf of Mexico. The rivers drain vast agricultural lands. The water carries fertilizer from these areas into the Gulf. I am facing a new situation today: In central Ireland there are two farms next to two very similar lakes, and both farms use the same fertilizer to grow crops. The farm next to lake Montopeke gets rain on a regular basis and so the farmer doesn't need to water his crops as much. The farm that is adjacent to lake Costanza hardly gets any rain at all though. Both farms are able to prosper and do well though despite the different amount of rain they get. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which lake will have less dead zones?

A: Costanza
Problem: Given the question: I read this background article the other day: In addition to insects, weeds have also been a menace to farmers - just ask anyone with a garden how much they hate weeds. They can quickly compete for water and nutrients needed by other plants. Sure, farmers can use herbicides to kill weeds, but do these chemicals also harm the crops? Can biotechnology help with this issue? Some crops have also been genetically engineered to acquire tolerance to the herbicides - allowing the crops to grow, but killing the weeds. But the lack of cost effective herbicides with a broad range of activity - that do not harm crops - is a problem in weed management. Multiple applications of numerous herbicides are routinely needed to control the wide range of weeds that are harmful to crops. And at times these herbicides are being used as a preventive measure that is, spraying to prevent weeds from developing rather than spraying after weeds form. So these chemicals are being added to crops. This practice is followed by mechanical and/or hand weeding to control weeds that are not controlled by the chemicals. Crops that are tolerant of herbicides would obviously be a tremendous benefit to farmers ( Figure above ). The introduction of herbicide tolerant crops has the potential to reduce the number of chemicals needed during a growing season, thereby increasing crop yield due to improved weed management and decreased harm to the crops. I am facing a new situation today: Dan studied genetic engineering. He was applying his knowledge of genetic engineering to develop better crops. Recently, he had successfully developed a crop, crop A, that was herbicide tolerant. To determine the versatility of the crop he compared it with another crop that was not tolerant of herbicides, crop B. The results of his research would allow his company to market the new crop. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Would crop A have lower or higher yields than crop B?
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The answer is:
higher
input question: I read this background article the other day: Apex predators affect prey species' population dynamics and populations of other predators, both in aquatic and in terrestrial ecosystems. Non-native predatory fish, for instance, have sometimes devastated formerly dominant predators. A lake manipulation study found that when the non-native smallmouth bass was removed, lake trout, the suppressed native apex predator, diversified its prey selection and increased its trophic level. As a terrestrial example, the badger, an apex predator, predates on and also competes with the hedgehog, a mesopredator, for food such as insects, small mammals, reptiles, amphibians and ground-nesting bird's eggs. Removal of badgers (in a trial investigating bovine tuberculosis) caused hedgehog densities to more than double. Predators that exert a top-down control on organisms in their community are often considered keystone species. Humans are not considered apex predators because their diets are typically diverse, although human trophic levels increase with consumption of meat. I am facing a new situation today: Rob is a biologist who is interested in native species conservation. To that end, he conducted two studies, case A and case B. In case A, a non native apex predator C was introduced in formerly apex predator D's habitat. In case B, same non native apex predator C was removed from formerly apex predator D's habitat. He now needs to analyze the results of these studies. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Would predator D's trophic level increase or decrease in case B than in case A????
output answer: increase
Q: I read this background article the other day: Hepatitis B is a disease of the liver. It is caused by a virus called hepatitis B, which can be passed through sexual activity. Hepatitis B causes vomiting. It also causes yellowing of the skin and eyes. The disease goes away on its own in some people. Other people are sick for the rest of their lives. In these people, the virus usually damages the liver. It may also lead to liver cancer. Medicines can help prevent liver damage in these people. There is also a vaccine to protect against hepatitis B. I am facing a new situation today: People from two villages got infected with viruses and got sick. People from Hill village got infected with the flu, while people in Valley village got infected with hepatitis B. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which villagers will experience more instances of liver cancer?
A:
Valley