Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

[Q]: Context: The immune system usually protects you from pathogens and other causes of disease. When the immune system is working properly, it keeps you from getting sick. But the immune system is like any other system of the body. It can break down or develop diseases. AIDS is an infectious disease of the immune system caused by a virus. Some diseases of the immune system are noninfectious. They include autoimmune diseases and allergies. Does it make sense for an immune system to attack the cells it is meant to protect? No, but an immune system that does not function properly will attack its own cells. An autoimmune disease is a disease in which the immune system attacks the bodys own cells. One example is type 1 diabetes. In this disease, the immune system attacks cells of the pancreas. Other examples are multiple sclerosis and rheumatoid arthritis. In multiple sclerosis, the immune system attacks nerve cells. This causes weakness and pain. In rheumatoid arthritis, the immune system attacks the cells of joints. This causes joint damage and pain. Autoimmune diseases cannot be cured. But they can be helped with medicines that weaken the immune systems attack on normal cells. Other autoimmune diseases include celiac disease (damages to the small intestine), inflam- matory bowel disease (damage to the digestive tract), psoriasis (damage to the skin), and lupus (damage to the joints, skin, kidneys, heart, and lungs). An allergy occurs when the immune system attacks a harmless substance that enters the body from the outside. A substance that causes an allergy is called an allergen. It is the immune system, not the allergen, that causes the symptoms of an allergy. Did you ever hear of hay fever? Its not really a fever at all. Its an allergy to plant pollens. People with this type of allergy have symptoms such as watery eyes, sneezing, and a runny nose. A common cause of hay fever is the pollen of ragweed. Many people are also allergic to poison ivy ( Figure 1.2). Skin contact with poison ivy leads to an itchy rash in people who are allergic to the plant. Ragweed is a common roadside weed found throughout the United States. Many people are allergic to its pollen. Some people are allergic to certain foods. Nuts and shellfish are common causes of food allergies. Other common causes of allergies include: Drugs, such as penicillin. Mold. Dust. The dead skin cells of dogs and cats, called dander. Stings of wasps and bees. Most allergies can be treated with medicines. Medicines used to treat allergies include antihistamines and corticos- teroids. These medicines help control the immune system when it attacks an allergen. Sometimes, allergies cause severe symptoms, a condition known as anaphylaxis. For example, they may cause the throat to swell so it is hard to breathe. Severe allergies may be life threatening. They require emergency medical care.
Question: autoimmune diseases can be cured with
[A]: autoimmune diseases cannot be cured.

[Q]: Context: In the county, the population was spread out with 23.20% under the age of 18, 7.70% from 18 to 24, 27.00% from 25 to 44, 28.00% from 45 to 64, and 14.10% who were 65 years of age or older. The median age was 40 years. For every 100 females, there were 97.00 males. For every 100 females age 18 and over, there were 96.40 males.
Question: Which age group is smaller: 25 to 44 or 45 to 64?
[A]: 25 to 44

[Q]: Context: Pollution that enters water at just one point is called point source pollution. For example, chemicals from a factory might empty into a stream through a pipe or set of pipes (see Figure 21.9). Pollution that enters in many places is called non-point source pollution. This means that the pollution is from multiple sources. With non-point source pollution, runoff may carry the pollution into a body of water. Which type of pollution do you think is harder to control? There are three main sources of water pollution: 1. Agriculture. 2. Industry. 3. Municipal, or community, sources. Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure 21.10). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick. Waste from livestock can also pollute water. The waste contains bacteria and other organisms that cause disease. In fact, more than 40 human diseases can be caused by water polluted with animal waste. Many farms in the U.S. have thousands of animals. These farms produce millions of gallons of waste. The waste is stored in huge lagoons, like the one in Figure 21.11. Unfortunately, many leaks from these lagoons have occurred. Two examples are described below. In North Carolina, 25 million gallons of hog manure spilled into a nearby river. The contaminated water killed Factories and power plants may pollute water with harmful substances. Many industries produce toxic chemicals. Some of the worst are arsenic, lead, and mercury. Nuclear power plants produce radioactive chemicals. They cause cancer and other serious health problems. Oil tanks and pipelines can leak. Leaks may not be noticed until a lot of oil has soaked into the ground. The oil may pollute groundwater so it is no longer fit to drink. Municipal refers to the community. Households and businesses in a community are also responsible for polluting the water supply. For example: People apply chemicals to their lawns. The chemicals may be picked up by rainwater. The contaminated runoff enters storm sewers and ends up in nearby rivers or lakes. Underground septic tanks can develop leaks. This lets household sewage seep into groundwater. Municipal sewage treatment plants dump treated wastewater into rivers or lakes. Sometimes the wastewater is not treated enough and contains bacteria or toxic chemicals. The oceans are vast. You might think they are too big to be harmed by pollution. But thats not the case. Ocean water is becoming seriously polluted. The oceans are most polluted along coasts. Why do you think thats the case? Of course, its because most pollution enters the oceans from the land. Runoff and rivers carry the majority of pollution into the ocean. Many cities dump their wastewater directly into coastal waters. In some parts of the world, raw sewage and trash may be thrown into the water (see Figure 21.12). Coastal water may become so polluted that people get sick if they swim in it or eat seafood from it. The polluted water may also kill fish and other ocean life. Oil spills are another source of ocean pollution. To get at oil buried beneath the seafloor, oil rigs are built in the oceans. These rigs pump oil from beneath the ocean floor. Huge ocean tankers carry oil around the world. If something goes wrong with a rig on a tanker, millions of barrels of oil may end up in the water. The oil may coat and kill ocean animals. Some of the oil will wash ashore. This oil may destroy coastal wetlands and ruin beaches. Figure 21.13 shows an oil spill on a beach. The oil washed ashore after a deadly oil rig explosion in the Gulf of Mexico in 2010. Thermal pollution is pollution that raises the temperature of water. This is caused by power plants and factories that
Question: pollution that enters water in many places
[A]:
non-point source pollution