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.

Ex Input:
Context: Ryu (Ha-kyun Shin), a deaf man, works in a factory to support his ailing sister (Ji-Eun Lim) in desperate need of a kidney transplant. Ryu tries to donate one of his kidneys to his sister but is told that his blood type does not match that of his sister and so is not a suitable donor. After being laid off from his job by the factory boss, Ryu contacts a black market organ dealer who agrees to sell him a kidney suitable for his sister in exchange for 10,000,000 Korean won, plus one of Ryu's own kidneys. He takes the severance pay from his factory job and offers the money to the organ dealers, who take the money and one of his kidneys, but then disappear. Three weeks later, Ryu learns from his doctor that a kidney has been found for his sister and that the operation will cost 10,000,000 won, but since the organ dealers stole his money, he will not be able to pay for it.In need of money for the operation and in retaliation for his being fired, Ryu and his girlfriend, Yeong-mi (Doona Bae), a radical anarchist, conspire to kidnap the daughter of the boss who fired him. Instead, he realizes that the kidnapping would immediately put them under police suspicion, and they decide to kidnap Yu-sun (Bo-bae Han), the daughter of the boss's friend, Park Dong-jin (Kang-ho Song), another factory executive. The girl stays with Ryu's sister (thinking that Ryu is merely babysitting for a time), who takes care of her while the distraught Dong-jin arranges to pay her ransom. After Ryu collects the money and returns home, he learns that his sister has discovered his scheme and, unwilling to be involved or burden Ryu further, killed herself. Ryu takes Yu-sun and his sister's body into the countryside to bury her by a riverbed they used to frequent as children. While Ryu mourns, Yu-sun accidentally slips into the river and drowns.Days later, as Dong-jin mourns his daughter and swears revenge at the river bank, Ryu ambushes and murders the organ dealers. Dong-jin, having investigated the identities of the kidnappers, finds Yeong-mi and begins interrogating her. Yeong-mi apologizes for Yu-sun's death but warns him of her membership in a terrorist organization that, knowing Dong-jin's identity, will kill him if she dies. Dong-jin, unfazed by the threats, tortures her to death by electrocuting her. Ryu returns to Yeong-mi's apartment building and discovers the police removing her body on a stretcher. Ryu, consumed with grief, swears vengeance on Dong-jin.Ryu arrives at Dong-jin's residence in an attempt to kill him. He waits for some time, but Dong-Jin does not arrive: he is, in fact, waiting at Ryu's apartment. After Dong-Jin does not arrive, Ryu returns to his apartment. However, Dong-jin had previously set up an electric booby trap on his doorknob, which renders Ryu unconscious. Dong-jin then binds Ryu and returns him to the riverbed where Yu-sun died. After binding Ryu's hands and feet and bringing him chest-high into the water, an emotional Dong-jin acknowledges that although Ryu is a good man, he has no choice; Dong-jin then slashes Ryu's Achilles tendons, resulting in his drowning.Dong-jin drags Ryu back to shore and then drives off to a desolate location to bury the body. Once there, he begins to dig a hole, but soon a group of men arrives. They surround and stab Dong-jin repeatedly, finally attaching a note to his chest identifying themselves as the terrorist group of which Yeong-mi was part. The group leave Dong-jin dying beside his car with the bloody tools and bags he used to chop up, dismember, and package Ryu's body.(From Wikipedia.) 
 Question: How does Yu-sun die?

Ex Output:
drowns


Ex Input:
Context: Organisms that live in lakes, ponds, streams, springs or wetlands are part of freshwater ecosystems. These ecosys- tems vary by temperature, pressure (in lakes), the amount of light that penetrates and the type of vegetation that lives there. Limnology is the study of bodies of fresh water and the organisms that live there. A lake has zones just like the ocean. The ecosystem of a lake is divided into three distinct zones (Figure 1.1): 1. The surface (littoral) zone is the sloped area closest to the edge of the water. 2. The open-water zone (also called the photic or limnetic zone) has abundant sunlight. 3. The deep-water zone (also called the aphotic or profundal zone) has little or no sunlight. There are several life zones found within a lake: In the littoral zone, sunlight promotes plant growth, which provides food and shelter to animals such as snails, insects, and fish. In the open-water zone, other plants and fish, such as bass and trout, live. The deep-water zone does not have photosynthesis since there is no sunlight. Most deep-water organisms are scavengers, such as crabs and catfish that feed on dead organisms that fall to the bottom of the lake. Fungi and bacteria aid in the decomposition in the deep zone. Though different creatures live in the oceans, ocean waters also have these same divisions based on sunlight with similar types of creatures that live in each of the zones. The three primary zones of a lake are the littoral, open-water, and deep-water zones. Wetlands are lands that are wet for significant periods of time. They are common where water and land meet. Wetlands can be large flat areas or relatively small and steep areas. Wetlands are rich and unique ecosystems with many species that rely on both the land and the water for survival. Only specialized plants are able to grow in these conditions. Wetlands tend have a great deal of biological diversity. Wetland ecosystems can also be fragile systems that are sensitive to the amount and quality of water present within them. Click image to the left or use the URL below. URL: Marshes are shallow wetlands around lakes, streams, or the ocean where grasses and reeds are common, but trees are not (Figure 1.2). Frogs, turtles, muskrats, and many varieties of birds are at home in marshes. A salt marsh on Cape Cod in Mas- sachusetts. A swamp is a wetland with lush trees and vines found in low-lying areas beside slow-moving rivers (Figure 1.3). Like marshes, they are frequently or always inundated with water. Since the water in a swamp moves slowly, oxygen in the water is often scarce. Swamp plants and animals must be adapted for these low-oxygen conditions. Like marshes, swamps can be fresh water, salt water, or a mixture of both. As mentioned above, wetlands are home to many different species of organisms. Although they make up only 5% of the area of the United States, wetlands contain more than 30% of the plant types. Many endangered species live in wetlands, so wetlands are protected from human use. Wetlands also play a key biological role by removing pollutants from water. For example, they can trap and use fertilizer that has washed off a farmers field, and therefore they prevent that fertilizer from contaminating another body of water. Since wetlands naturally purify water, preserving wetlands also helps to maintain clean supplies of water. 
 Question: the sloped side of a lake where sunlight penetrates is the

Ex Output:
littoral zone


Ex Input:
Context: Nutrients in the foods you eat are needed by the cells of your body. How do the nutrients in foods get to your body cells? What organs and processes break down the foods and make the nutrients available to cells? The organs are those of the digestive system. The processes are digestion and absorption. The digestive system is the body system that breaks down food and absorbs nutrients. It also gets rid of solid food waste. The digestive system is mainly one long tube from the mouth to the anus, known as the gastrointestinal tract (GI tract). The main organs of the digestive system include the esophagus, stomach and the intestine, and are pictured below ( Figure 1.1). The intestine is divided into the small and large intestine. The small intestine has three segments. The ileum is the longest segment of the small intestine, which is well over 10 feet long. The large intestine is about 5 feet long. This drawing shows the major organs of the digestive system. The liver, pancreas and gallbladder are also organs of the digestive system. Digestion is the process of breaking down food into nutrients. There are two types of digestion, mechanical and chemical. In mechanical digestion, large chunks of food are broken down into small pieces. Mechanical digestion begins in the mouth and involves physical processes, such as chewing. This process continues in the stomach as the food is mixed with digestive juices. In chemical digestion, large food molecules are broken down into small nutrient molecules. This is a chemical process which also begins in the mouth as saliva begins to break down food and continues in the stomach as stomach enzymes further digest the food. Absorption is the process that allows substances you eat to be taken up by the blood. After food is broken down into small nutrient molecules, the molecules are absorbed by the blood. After absorption, the nutrient molecules travel in the bloodstream to cells throughout the body. This happens mostly in the small intestine. Some substances in food cannot be broken down into nutrients. They remain behind in the digestive system after the nutrients are absorbed. Any substances in food that cannot be digested and absorbed pass out of the body as solid waste. The process of passing solid food waste out of the body is called elimination. 
 Question: the mixing of food with stomach juices is an example of

Ex Output:

chemical digestion.