TASK DEFINITION: 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.
PROBLEM: Context: What's on ? The Conjuring 2 (2016) Certificate R 134 min--Horror Viewer points: 8.2 / 10 Lorraine and Ed Warren travel to north London to help a single mother raising four children alone in a house troubled by evil spirits . Director : James Wan Stars : Vera Farmiga , Patrick Wilson , Madison Wolfe , Frances O'Connor Warcraft (2016) Certificate PG-13 123 min--Action | Adventure | Fantasy Viewer points : 7.7 / 10 The peaceful land of Azeroth stands on the edge of war as its civilization faces a fearsome race of invaders : orc warriors escaping their dying home to conquer another . As a tunnel opens to connect the two worlds , one army faces destruction and the other faces extinction . From opposing sides , two heroes are set on a collision course that will decide the fate of their family , their people , and their home . Director : Duncan Jones Stars : Travis Fimmel , Paula Patton , Ben Foster , Dominic Cooper Now You See Me 2 (2016) Certificate PG-13 129 min--Action | Comedy | Thriller Viewer points : 7.1 / 10 The Four Horsemen resurface and are forcibly hired by a tech genius to pull off their most impossible magic show yet . Director : Jon M. Chu Stars : Jesse Eisenberg , Mark Ruffalo , Woody Harrelson , Dave Franco Me Before You (2016) Certificate PG-13 110 min--Drama | Romance Viewer points : 7.9 /10 A girl in a small town forms an unlikely bond with a recently-disabled man she's taking care of . Director : Thea Sharrock Stars : Emilia Clarke , Sam Claflin , Janet McTeer , Charles Dance 
 Question: Which actor will show in a movie that scares you ?

SOLUTION: patrick wilson

PROBLEM: Context: 51827 Laurelclark (2001 OH38) is an asteroid named for astronaut Laurel Clark, who was killed in the STS-107 (Columbia) space shuttle reentry disaster on February 1, 2003. 
 Question: Whom is 51827 Laurelclark named after?

SOLUTION: laurel clark

PROBLEM: Context: Ultrasound is sound that has a wave frequency higher than the human ear can detect. It includes all sound with wave frequencies higher than 20,000 waves per second, or 20,000 hertz (Hz). Although we cant hear ultrasound, it is very useful to humans and some other animals. Uses of ultrasound include echolocation, sonar, and ultrasonography. Animals such as bats and dolphins send out ultrasound waves and use their echoes, or reflected waves, to identify the locations of objects they cannot see. This is called echolocation. Animals use echolocation to find prey and avoid running into objects in the dark. You can see in the Figure 1.1 how a bat uses echolocation to find insect prey. Sonar uses ultrasound in a way that is similar to echolocation. Sonar stands for sound navigation and ranging. It is used to locate underwater objects such as submarines. Thats how the ship pictured in the Figure 1.2 is using it. A sonar device is both a sender and a receiver. It sends out ultrasound waves and detects the waves after they reflect from underwater objects. The distance to underwater objects can be calculated from the known speed of sound in water and the time it takes for the sound waves to travel to the object. The equation for distance traveled when speed and time are known is: Distance = Speed Time Consider the ship and submarine pictured in the Figure 1.2. If an ultrasound wave travels from the ship to the submarine and back again in 2 seconds, what is the distance from the ship to the submarine? The sound wave travels from the ship to the submarine in just 1 second, or half the time it takes to make the round trip. The speed of sound waves through ocean water is 1437 m/s. Therefore, the distance from the ship to the submarine is: Q: Now assume that the sonar device on the ship sends an ultrasound wave to the bottom of the water. If the sound wave is reflected back to the device in 4 seconds, how deep is the water? A: The time it takes the wave to reach the bottom is 2 seconds. So the distance from the ship to the bottom of the water is: Distance = 1437 m/s 2 s = 2874 m Another use of ultrasound is to see inside the human body. This use of ultrasound is called ultrasonography. Harmless ultrasound waves are sent inside the body, and the reflected waves are used to create an image on a screen. This technology is used to examine internal organs and unborn babies without risk to the patient. You can see a doctor using ultrasound in the Figure 1.3. 
 Question: the speed of sound waves through ocean water is 1437 m/s. assume that ultrasound waves take 2 seconds to travel from a sonar device on a ship to the bottom of the water and back to the ship again. how deep is the water?

SOLUTION:
1437 m