You are given a background paragraph that describes one or more causal or qualitative relationships such as a relationship in economics or a scientific law and a story that makes use of the concepts or the relationship described in the provided paragraph. You need to come up with a question about the story that requires an understanding of the relationship described in the background paragraph. The generated question should not be answerable without both the background and story. Write a question about the story that requires a relationship in the background paragraph to answer. Check whether your question requires both the background paragraph and the story to answer. If your question can be answered by only one of these, try to rewrite your question so that it requires both. Note that "flipping" a word in the question can give rise to a new question where the answer will be different from the original question. Often, "flipping" a word gives rise to flipping the direction of the relationship, for example, from "increase" to "decrease."

[EX Q]: Background Paragraph: Look at the police car in Figure below . The sound waves from its siren travel outward in all directions. Because the car is racing forward (toward the right), the sound waves get bunched up in front of the car and spread out behind it. As the car approaches the person on the right (position B), the sound waves get closer and closer together. In other words, they have a higher frequency. This makes the siren sound higher in pitch. After the car speeds by the person on the left (position A), the sound waves get more and more spread out, so they have a lower frequency. This makes the siren sound lower in pitch. A change in the frequency of sound waves, relative to a stationary listener, when the source of the sound waves is moving is called the Doppler effect . You’ve probably experienced the Doppler effect yourself. The next time a vehicle with a siren races by, listen for the change in pitch. For an online animation of the Doppler effect, go to the URL below. 
Story: A scientist is analyzing two different sounds, one from a deer and one from a zebra, with a device that allows her to see the sound waves of each noise. While looking at the results, she sees that the sound waves for the deer are more closely packed together, but the zebra's sound has very spread out waves.
[EX A]: Which animal's sound has a higher pitch?

[EX Q]: Background Paragraph: Because the gravitational field created by the Moon weakens with distance from the Moon, it exerts a slightly stronger than average force on the side of the Earth facing the Moon, and a slightly weaker force on the opposite side. The Moon thus tends to "stretch" the Earth slightly along the line connecting the two bodies. The solid Earth deforms a bit, but ocean water, being fluid, is free to move much more in response to the tidal force, particularly horizontally.  As the Earth rotates, the magnitude and direction of the tidal force at any particular point on the Earth's surface change constantly; although the ocean never reaches equilibrium—there is never time for the fluid to "catch up" to the state it would eventually reach if the tidal force were constant—the changing tidal force nonetheless causes rhythmic changes in sea surface height. 
Story: Mike was reading about an instrument that could measure gravity, gravimeter. He then found how gravimeter was used to measure the gravitational field of the Moon. He read about two distinct cases where the Moon's gravitational field was measured on earth, side A and side B. In side A the Moon's gravity was measured from the side where the Earth was facing the Moon. And in side B the Moon's gravitational field was measured from the opposite side of the Earth. He found these two locations showed very different consequences of Moon's gravitational field.
[EX A]: On which side the Moon's gravitational field would exert stronger force, side A side B?

[EX Q]: Background Paragraph: A godet (/ɡoʊˈdeɪ/ or /ɡoʊˈdɛt/)[1] is an extra piece of fabric in the shape of a circular sector which is set into a garment, usually a dress or skirt.[2] The addition of a godet causes the article of clothing in question to flare, thus adding width and volume.[3] Adding a godet to a piece of clothing also gives the wearer a wider range of motion.[4]. 
Story: Dan is a dance instructor. In an upcoming dance competition he has to send two groups of students, group A and group B. He dressed group A students with godet. But he didn't dress group B students with godet. There are two categories of dance, category C and category D, in the dance competition. Category C requires lots of motion, but category D does not required much motion. Dan has to decide which of his student groups would compete in category C and which group to compete in category D.
[EX A]:
Which group should Dan select for category C competition, group A or group B?