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

''Nothing Good Happens After 2 A.M.'' is the 18th episode in the first season of the television series How I Met Your Mother.
What series is the episode Nothing Good Happens After 2 A.M. part of?

Freshwater below Earths surface is called groundwater. The water infiltrates, or seeps down into, the ground from the surface. How does this happen? And where does the water go? Water infiltrates the ground because soil and rock are porous. Between the grains are pores, or tiny holes. Since water can move through this rock it is permeable. Eventually, the water reaches a layer of rock that is not porous and so is impermeable. Water stops moving downward when it reaches this layer of rock. Look at the diagram in Figure 13.11. It shows two layers of porous rock. The top layer is not saturated; it is not full of water. The next layer is saturated. The water in this layer has nowhere else to go. It cannot seep any deeper into the ground because the rock below it is impermeable. The top of the saturated rock layer in Figure 13.11 is called the water table. The water table isnt like a real table. It doesnt remain firmly in one place. Instead, it rises or falls, depending on how much water seeps down from the surface. The water table is higher when there is a lot of rain and lower when the weather is dry. An underground layer of rock that is saturated with groundwater is called an aquifer. A diagram of an aquifer is shown in Figure 13.12. Aquifers are generally found in porous rock, such as sandstone. Water infiltrates the aquifer from the surface. The water that enters the aquifer is called recharge. Most land areas have aquifers beneath them. Many aquifers are used by people for freshwater. The closer to the surface an aquifer is, the easier it is to get the water. However, an aquifer close to the surface is also more likely to become polluted. Pollutants can seep down through porous rock in recharge water. An aquifer that is used by people may not be recharged as quickly as its water is removed. The water table may lower and the aquifer may even run dry. If this happens, the ground above the aquifer may sink. This is likely to damage any homes or other structures built above the aquifer. One of the biggest aquifers in the world is the Ogallala aquifer. As you can see from Figure 13.13, this aquifer lies beneath parts of eight U.S. states. It covers a total area of 451,000 square kilometers (174,000 square miles). In some places, it is less than a meter deep. In other places, it is hundreds of meters deep. The Ogallala aquifer is an important source of freshwater in the American Midwest. This is a major farming area, and much of the water is used to irrigate crops. The water in this aquifer is being used up ten times faster than it is recharged. If this continues, what might happen to the Ogallala aquifer? The top of an aquifer may be high enough in some places to meet the surface of the ground. This often happens on a slope. The water flows out of the ground and creates a spring. A spring may be just a tiny trickle, or it may be a big gush of water. One of the largest springs in the world is Big Spring in Missouri, seen in Figure 13.14. Water flowing out of the ground at a spring may flow downhill and enter a stream. Thats what happens to the water that flows out of Big Spring in Missouri. If the water from a spring cant flow downhill, it may spread out to form a pond or lake instead. Lake George in New York State, which is pictured in Figure 13.15, is a spring-fed lake. The lake basin was carved by a glacier. Some springs have water that contains minerals. Groundwater dissolves minerals out of the rock as it seeps through the pores. The water in some springs is hot because it is heated by hot magma. Many hot springs are also mineral springs. Thats because hot water can dissolve more minerals than cold water. Grand Prismatic Spring, shown in Figure 13.16, is a hot mineral spring. Dissolved minerals give its water a bright blue color. The edge of the spring is
top of an underground rock layer that is saturated with water

The water droplets of fog form from water vapor in the air. Fog disappears when the water droplets change back to water vapor. These changes are examples of changes of state. A change of state occurs whenever matter changes from one state to another. Common states of matter on Earth are solid, liquid, and gas. Matter may change back and forth between any two of these states. Changes of state are physical changes in matter. They are reversible changes that do not change matters chemical makeup or chemical properties. For example, when fog changes to water vapor, it is still water and can change back to liquid water again. Several processes are involved in common changes of state. They include melting, freezing, sublimation, deposition, condensation, and evaporation. The Figure 1.1 shows how matter changes in each of these processes. Q: Which two processes result in matter changing to the solid state? A: The processes are deposition, in which matter changes from a gas to a solid, and freezing, in which matter changes from a liquid to a solid. Suppose that you leave some squares of chocolate candy in the hot sun. A couple of hours later, you notice that the chocolate has turned into a puddle like the one pictured in the Figure 1.2. Q: What happened to the chocolate? A: The chocolate melted. It changed from a solid to a liquid. In order for solid chocolate to melt and change to a liquid, the particles of chocolate must gain energy. The chocolate pictured in the Figure 1.2 gained energy from sunlight. Energy is the ability to cause changes in matter, and it is always involved in changes of state. When matter changes from one state to another, it either absorbs energyas when chocolate meltsor loses energy. For example, if you were to place the melted chocolate in a refrigerator, it would lose energy to the cold air inside the refrigerator. As a result, the liquid chocolate would change to a solid Q: Why is energy always involved in changes of state? A: The energy of particles of matter determines the matters state. Particles of a gas have more energy than particles of a liquid, and particles of a liquid have more energy than particles of a solid. Therefore, in order for matter to change from a solid to a liquid or from a liquid to a gas, particles of matter must absorb energy. In order for matter to change from a gas to a liquid or from a liquid to a solid, particles of matter must lose energy.

which process does not involve matter in the liquid state?