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 Q]: Context: The film opens with narration over a silhouette of Hill House at night. The narrator, Dr. John Markway (Richard Johnson) tells us, "An evil old house, the kind some people call haunted is like an undiscovered country waiting to be explored. Hill House had stood for 90 years and might stand for 90 more. Silence lay steadily against the wood and stone of Hill House. Whatever walked there walked alone." Title and credits follow, then narration continues, "Scandal, murder, insanity, suicide: The history of Hill House was ideal. It had everything I wanted..." The house was built in New England by a man named Hugh Crain for his wife and young daughter. A horse and carriage accident took the life of the first Mrs. Crain (an uncredited Pamela Buckley) before she even saw the house. Hugh Crain (an uncredited Howard Lang) and young daughter, Abigail (an uncredited Janet Mansell) said a few words over the body, but Hugh was left an embittered man. Crain married again, and the second Mrs. Crain (an uncredited Freda Knorr) also died, falling down the main staircase. Hugh Crain left Abigail with a nurse (an uncredited Susan Richards) and went to England where he died in a drowning accident. Abigail kept the same nursery room her entire life. By the time she was eighty (an uncredited Amy Dalby) she was a bedridden invalid. Her nurse-companion (an uncredited Rosemary Dorken) was a local girl and, it is with this young companion the evil reputation of Hill House really begins. The old lady died while calling for help. The companion was trysting on the verandah with a farm hand. The companion inherited Hill House and occupied it for many years, but eventually hanged herself. The house then passed to a distant relative, named Mrs. Sanderson (Fay Compton).Markway visits Mrs. Sanderson where he convinces her to let him use the house for psychic research. He explains, "I shall occupy the house with a group of carefully selected assistants...I must have specially qualified help to take notes and document any evidence of the supernatural I may find." Eldridge Harper (Ronald Adam), Mrs. Sanderson's lawyer, voices his concern about publicity seekers and the propriety of having women in the house. Harper suggests to Mrs. Sanderson that her nephew, Luke, joins the doctor at Hill House, as he expects to inherit the property. Mrs. Sanderson asks point blank, "Exactly what do you and your assistants expect to find at Hill House?" Markway replies, "Maybe only a few loose floorboards, and maybe, I only say maybe, the key to another world."Dr. Markway, taking a leave of absence from his university professorship, finalizes his list of assistants. Only two end up accepting, Eleanor Lance and Theodora (no last name).Eleanor Lance (Julie Harris) is living with her sister. She is nearly broke and weary after looking after her invalid mother non-stop for eleven years. Mother is now dead, and she fights with her sister over just about everything. She begs to use the car, which is after all, half hers. Her brother-in-law, Bud Fredericks (an uncredited Paul Maxwell) tries to act as mediator between Eleanor and his wife, Carrie (Diane Clare). He is sympathetic to Eleanor's plight, but their daughter, Dora (an uncredited Verina Greenlaw) takes her cues from her mother, and taunts her Aunt Eleanor. On the vacation plan, Bud sides with Eleanor, "I think you should have a vacation, Nell." Carrie objects, but Eleanor is not to be deterred and she shows her family how she reacts when pushed to her breaking point. She is normally quiet and meek, but when pushed is loud and assertive.Nell decides to take the car and confronts the garage attendant (an uncredited Claude Jones) for the keys. She departs Boston along U.S. 50 and Route 238 to Hill House. We hear Nell thinking and she reveals she will never return to live with her sister. In fact, most of what we learn of Eleanor is hearing her thoughts.Eleanor 
 Question: What is the ghost's name?
[EX A]: hugh crain

[EX Q]: Context: In 2009, 78.5% of Dallas (city) commuters drive to work alone. The 2009 modal share for Dallas (city) commuters are 10.7% for carpooling, 3.9% for transit, 1.9% for walking, and .1% for cycling. In 2015, the American Community Survey estimated modal shares for Dallas (city) commuters of 75.4% for driving alone, 12.8% for carpooling, 3.5% for riding transit, 1.9% for walking, and .2% for cycling. The city of Dallas has a higher than average percentage of households without a car. In 2015, 10.2 percent of Dallas households lacked a car, and decreased to 9.1 percent in 2016. The national average was 8.7 percent in 2016. Dallas averaged 1.59 cars per household in 2016, compared to a national average of 1.8. 
 Question: Which group in percent of commuters in Dallas in 2009 is larger: carpooling or walking?
[EX A]: carpooling

[EX Q]: 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: sonar is used to determine the
[EX A]:
distance to underwater objects.