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: We all enjoy a cool dip in a swimming pool on a hot day, but we may not realize the work needed to keep that water safe and healthy. The ideal pH for a swimming pool is around 7.2. The pH will change as a result of many factors. Adjustment can be accomplished with different chemicals depending on the tested pH. High pH can be lowered with liquid HCl (unsafe material) or sodium bisulfate. The bisulfate anion is a weak acid and can dissociate partially in solution. To increase pH, use sodium carbonate. The carbonate anion forms an equilibrium with protons that results in some formation of carbon dioxide.
Story: Tom and John are both pool owners. Tom prefers to use sodium bisulfate in his pool because he enjoys the smell. John, however, prefers using sodium carbonate in his pool because he believes it helps keep pests away.
[EX A]: Whose pool will have a higher pH?

[EX Q]: Background Paragraph: Mass is a measure of the amount of matter in a substance or an object. The basic SI unit for mass is the kilogram (kg), but smaller masses may be measured in grams (g). To measure mass, you would use a balance. In the lab, mass may be measured with a triple beam balance or an electronic balance, but the old-fashioned balance pictured below may give you a better idea of what mass is. If both sides of this balance were at the same level, it would mean that the fruit in the left pan has the same mass as the iron object in the right pan. In that case, the fruit would have a mass of 1 kg, the same as the iron. As you can see, however, the fruit is at a higher level than the iron. This means that the fruit has less mass than the iron, that is, the fruit's mass is less than 1 kg.
Story: Johnathan is trying to find two blocks of wood with the same mass for a project he is working on. He doesn't have a balance, so he makes a crude one out of materials he has on hand. He put a block of wood on either side and the block on the left side was at a lower level than the block on the right.

Sarah is using a traditional balance to estimate the mass of her peppers. She wants to make 1 kg bushels to sell at the farmers market so she puts a 1 kg weight on the right side and the peppers on the left side.
[EX A]: If the 1 kg weight is higher than the peppers does Sarah need to add more peppers or remove peppers?

[EX Q]: Background Paragraph: All machines make work easier, but they don't increase the amount of work that is done. You can never get more work out of a machine than you put into it. In fact, a machine always does less work on an object than the user does on the machine. That's because a machine must use some of the work put into it to overcome friction. Friction is the force that opposes motion between any surfaces that are touching. All machines involve motion, so they all have friction. How much work is needed to overcome friction in a machine depends on the machine's efficiency.
Story: During the summer Anthony found it was way too hot to be comfortable. He went out to his garage to get an old fan. The fan was spins on a metal bearing but because it is old it was slightly rusted. When he turned the fan on it spun very slow, struggling to move. He then decided to lubricate the bearing that rotates the fan blades and the fan started spinning normally.
[EX A]:
Given a lawn mower with a rusted blade, will it reqiore more or less work to operate than one with a normal blade?