Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Input: Consider Input: Water is a simple chemical compound. Each molecule of water contains two hydrogen atoms (H2 ) and one oxygen atom (O). Thats why the chemical formula for water is H2 O. If water is so simple, why is it special? Water is one of the few substances that exists on Earth in all three states of matter. Water occurs as a gas, a liquid and a solid. You drink liquid water and use it to shower. You breathe gaseous water vapor in the air. You may go ice skating on a pond covered with solid water ice in the winter. Earth is often called the water planet. Figure 13.1 shows why. If astronauts see Earth from space, this is how it looks. Notice how blue the planet appears. Thats because oceans cover much of Earths surface. Water is also found in the clouds that rise above the planet. Most of Earths water is salt water in the oceans. As Figure 13.2 shows, only 3 percent of Earths water is fresh. Freshwater is water that contains little or no dissolved salt. Most freshwater is frozen in ice caps and glaciers. Glaciers cover the peaks of some tall mountains. For example, the Cascades Mountains in North America and the Alps Mountains in Europe are capped with ice. Ice caps cover vast areas of Antarctica and Greenland. Chunks of ice frequently break off ice caps. They form icebergs that float in the oceans. Did you ever wonder where the water in your glass came from or where its been? The next time you take a drink of water, think about this. Each water molecule has probably been around for billions of years. Thats because Earths water is constantly recycled. Water is recycled through the water cycle. The water cycle is the movement of water through the oceans, atmo- sphere, land, and living things. The water cycle is powered by energy from the Sun. Figure 13.3 diagrams the water cycle. Water keeps changing state as it goes through the water cycle. This means that it can be a solid, liquid, or gas. How does water change state? How does it keep moving through the cycle? As Figure 13.3 shows, several processes are involved. Evaporation changes liquid water to water vapor. Energy from the Sun causes water to evaporate. Most evaporation is from the oceans because they cover so much area. The water vapor rises into the atmosphere. Transpiration is like evaporation because it changes liquid water to water vapor. In transpiration, plants release water vapor through their leaves. This water vapor rises into the atmosphere. Condensation changes water vapor to liquid water. As air rises higher into the atmosphere, it cools. Cool air can hold less water vapor than warm air. So some of the water vapor condenses into water droplets. Water droplets may form clouds. Precipitation is water that falls from clouds to Earths surface. Water droplets in clouds fall to Earth when they become too large to stay aloft. The water falls as rain if the air is warm. If the air is cold, the water may freeze and fall as snow, sleet, or hail. Most precipitation falls into the oceans. Some falls on land. Runoff is precipitation that flows over the surface of the land. This water may travel to a river, lake, or ocean. Runoff may pick up fertilizer and other pollutants and deliver them to the water body where it ends up. In this way, runoff may pollute bodies of water. Infiltration is the process by which water soaks into the ground. Some of the water may seep deep under- ground. Some may stay in the soil, where plants can absorb it with their roots. In all these ways, water keeps cycling. The water cycle repeats over and over again. Who knows? Maybe a water molecule that you drink today once quenched the thirst of a dinosaur.

Output: water that falls from clouds to Earths surface


Input: Consider Input: The Eagles looked to win their 6th game in a row against the winless 49ers. The Eagles got off to a slow start, only leading 3-0 after the first quarter. Late in the second quarter, the Eagles blew the game open. Carson Wentz found tight end Zach Ertz for a 1-yard touchdown in the back of the end zone off of a bootleg pass, and Jalen Mills intercepted rookie QB C.J. Beathard and returned it 37 yards for a touchdown. The 49ers appeared to have some life in the third quarter, following a Carson Wentz interception, leading to a Matt Breida 22 yard touchdown reception. However, the Eagles responded, with Wentz connecting with Alshon Jeffery for a 53-yard touchdown, putting the game out of reach. The Eagles went on to win 33-10 and advanced to 7-1 on the season. Despite the win, the Eagles played a sloppy game in a rainy afternoon at the Linc.

Output: Which player had the longest touchdown catch?


Input: Consider Input: Different rock types weather at different rates. Certain types of rock are very resistant to weathering. Igneous rocks, especially intrusive igneous rocks such as granite, weather slowly because it is hard for water to penetrate them. Other types of rock, such as limestone, are easily weathered because they dissolve in weak acids. Rocks that resist weathering remain at the surface and form ridges or hills. Shiprock in New Mexico is the throat of a volcano thats left after the rest of the volcano eroded away. The rock thats left behind is magma that cooled relatively slowly and is harder than the rock that had surrounded it. Different minerals also weather at different rates. Some minerals in a rock might completely dissolve in water, but the more resistant minerals remain. In this case, the rocks surface becomes pitted and rough. When a less resistant mineral dissolves, more resistant mineral grains are released from the rock. A beautiful example of this effect is the "Stone Forest" in China, see the video below: The Shiprock formation in northwest New Mexico is the central plug of resistant lava from which the surrounding rock weath- ered and eroded away. Click image to the left or use the URL below. URL: A regions climate strongly influences weathering. Climate is determined by the temperature of a region plus the amount of precipitation it receives. Climate is weather averaged over a long period of time. Chemical weathering increases as: Temperature increases: Chemical reactions proceed more rapidly at higher temperatures. For each 10o C increase in average temperature, the rate of chemical reactions doubles. Precipitation increases: More water allows more chemical reactions. Since water participates in both mechan- ical and chemical weathering, more water strongly increases weathering. So how do different climates influence weathering? A cold, dry climate will produce the lowest rate of weathering. A warm, wet climate will produce the highest rate of weathering. The warmer a climate is, the more types of vegetation it will have and the greater the rate of biological weathering (Figure 1.2). This happens because plants and bacteria grow and multiply faster in warmer temperatures. Some resources are concentrated by weathering processes. In tropical climates, intense chemical weathering carries away all soluble minerals, leaving behind just the least soluble components. The aluminum oxide, bauxite, forms this way and is our main source of aluminum ore.


Output: climate is determined by