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.

Example Input: Context: The movie opens with Ralph Wiggum singing along to the 20th Century Fox logo. We then cut to Itchy & Scratchy: The Movie. They are out on the moon. Itchy kills Scratchy and then returns to earth and is painted as a hero by the media. Shortly thereafter, Itchy is elected president. Later as Itchy is in the White House, he sees a supposedly dead Scratchy on the moon. Scratchy holds up a sign that says "I'm telling", which freaks President Itchy out. Itchy then retaliates by sending a hundred missiles toward Scratchy. This is then seen in the theater which is being attended by the Simpsons. Homer stands up and yells "Boring!". Lisa replies "Dad, we can't see the movie!". Homer then goes off on a tirade about why they're paying to watch something in the theater that they normally watch on TV, and that everyone in the audience is a gigantic sucker, especially you. Cue a very fancy and stylized version of the standard Simpsons opening theme.The opening ends with Green Day hosting a concert at Lake Springfield (Singing the Simpsons theme after the opening credits). After they finish their song, they talk about the environment. The audience becomes angry and begins to throw garbage at them polluting the lake and causing their barge to dissolve and sink, killing them. The next day at church, while they have a short memorial for Green Day, Grampa is possessed by God warns the city of a future disaster. Marge believes Grampa's prediction, and decides to work out the meaning of the message. Meanwhile, Lisa starts to talk about the environment, with no success. She encounters Colin, an Irish boy who shares the same passions as her. Homer gets a note from Marge of his chores, and one is fixing the sinkhole. Instead of fixing it, Homer puts Maggie's sandbox over it. His next chore is to fix the roof. While repairing the roof, Homer and Bart decide to have a dare contest. Homer dares Bart to climb the antenna. Bart does so, and gets stuck. Homer shakes it in order to get Bart down. Homer dares Bart to skateboard to Krusty Burger naked, which Bart object's to, saying girls will see his "doodle". After Homer threatens to call him chicken for the rest of his life, Bart agrees. Bart becomes stuck naked on the window of the building. After he is apprehended by the police, and tied to a Stop sign pole, Homer turns up and they decide to order a meal, he brings him socks and a shirt, and no pants. Inside the restuarant, Ned Flanders helps Bart out by giving him a pair of pants, and understands his feelings which begins a relationship and mutual respect between the two. Meanwhile Krusty is filming a commercial. When recording finishes Krusty orders for the pig he is using in the commercial to be slaughtered, causing it to flee to Homer who adopts him, and calls him Spider-Pig. That evening Lisa holds a conference at city hall, called "An Irritating Truth" and explains that the town lake cannot sustain anymore pollution. Mayor Quimby declares a state of emergency and orders the cleansing and protection of Lake Springfield.They put up a fence around the lake to halt further dumping, and announce it is idiot proof, using Cletus as an example to try to throw a possum in the lake, and fail. Soon, Marge asks Homer where "Spider-Pig's/Harry Plopper's" waste is going. Homer shows her an overflowing silo, asking how a pig can fill it up in two days, Homer replies that he helped, horrifying Marge who tells Homer to dispose of it safely. While waiting in a queue at the dump Homer is told by Lenny that Lard Lad Donuts has been shut down and that they are giving away free donuts. Homer, in his haste to get to the giveaway decides on a quicker means of disposal and dumps the silo into the lake, causing it to become heavily polluted. A nearby squirrel jumps into it and becomes severely mutated, with many eyes. Nearby, 
 Question: What do Lisa and Colin convince the entire town to clean?
Example Output: the lake

Example Input: Context: Ice is an example of solid matter. A solid is matter that has a fixed volume and a fixed shape. Figure 4.3 shows examples of matter that are usually solids under Earth conditions. In the figure, salt and cellulose are examples of crystalline solids. The particles of crystalline solids are arranged in a regular repeating pattern. The steaks and candle wax are examples of amorphous ("shapeless") solids. Their particles have no definite pattern. Ocean water is an example of a liquid. A liquid is matter that has a fixed volume but not a fixed shape. Instead, a liquid takes the shape of its container. If the volume of a liquid is less than the volume of its container, the top surface will be exposed to the air, like the oil in the bottles in Figure 4.4. Two interesting properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like those in Figure 4.5. Viscosity is a liquids resistance to flowing. Thicker liquids are more viscous than thinner liquids. For example, the honey in Figure 4.5 is more viscous than the vinegar. You can learn more about surface tension and viscosity at these URLs: [Link] [Link] (1:40) MEDIA Click image to the left or use the URL below. URL: Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. Youre probably less familiar with plasmas than with solids, liquids, and gases. Yet, most of the universe consists of plasma. Plasma is a state of matter that resembles a gas but has certain properties that a gas does not have. Like a gas, plasma lacks a fixed volume and shape. Unlike a gas, plasma can conduct electricity and respond to magnetism. Thats because plasma contains charged particles called ions. This gives plasma other interesting properties. For example, it glows with light. Where can you find plasmas? Two examples are shown in Figure 4.7. The sun and other stars consist of plasma. Plasmas are also found naturally in lightning and the polar auroras (northern and southern lights). Artificial plasmas are found in fluorescent lights, plasma TV screens, and plasma balls like the one that opened this chapter. You can learn more about plasmas at this URL: (2:58). MEDIA Click image to the left or use the URL below. URL: Why do different states of matter have different properties? Its because of differences in energy at the level of atoms and molecules, the tiny particles that make up matter. Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the "war" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: [Link] In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do 
 Question: ability to cause changes in matter
Example Output: energy

Example Input: Context: Trimethylation of histone H3 Lys4 (H3K4) is associated with transcriptional activation. One of the chief effectors of H3K4 methylation is mixed-lineage leukemia 1 (MLL1), a gene that is disrupted by chromosomal translocation in acute leukemia and a master regulator of Hox and other genes. In a recent paper, core components of the human MLL histone methyltransferase (MT) complex were found to form a structural platform, with one component (WDR5) mediating association between the specific histone H3K4 substrate and the MT. This novel regulatory mechanism, which is conserved from yeast to human, is required for both methylation and downstream target gene transcription. 
 Question: Which is the histone residue methylated by MLL1?
Example Output:
h3k4