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 are also given a question about the story that requires an understanding of the relationship described in the background paragraph and the story. You need to come up with an answer to the given question; the answer will be a span from either the question or the story. In order to correctly answer the given question, you need to understand the relationship mentioned in the background paragraph and should be able to use it to understand that in the story. Your answer can not consist of any word that is not mentioned in any of these: the background paragraph, the story, or the question. You can directly copy and paste a span from the story or the question while answering the given question.

[Q]: Background Paragraph: Centripetal force is, simply, the force that causes centripetal acceleration. Objects that move in uniform circular motion all have an acceleration toward the center of the circle and therefore, they must also suffer a force toward the center of the circle. That force is the centripetal force. For orbiting satellites, such as the moon orbiting the earth or the earth orbiting the sun, the centripetal force is produced by gravity. When an Olympic hammer thrower whirls a massive ball on a chain, the centripetal force is created by the athlete and transmitted by the chain. 
Story: Adam wants to show his little brother a trick.  He gets a bucket of water and says to him "I bet i can turn this bucket upside down and no water will fall out". His brother doesn't believe him of course. So Adam takes the bucket by the handle and quickly starts spinning it in a circle. 
Question: Given Adam stops swinging the bucket, will its centripetal acceleration increase or decrease?
[A]: decrease.


[Q]: Background Paragraph: Most ants are generalist predators, scavengers, and indirect herbivores, but a few have evolved specialised ways of obtaining nutrition. It is believed that many ant species that engage in indirect herbivory rely on specialized symbiosis with their gut microbes to upgrade the nutritional value of the food they collect and allow them to survive in nitrogen poor regions, such as rainforest canopies. Leafcutter ants (Atta and Acromyrmex) feed exclusively on a fungus that grows only within their colonies. They continually collect leaves which are taken to the colony, cut into tiny pieces and placed in fungal gardens. Ergates specialise in related tasks according to their sizes. The largest ants cut stalks, smaller workers chew the leaves and the smallest tend the fungus. Leafcutter ants are sensitive enough to recognise the reaction of the fungus to different plant material, apparently detecting chemical signals from the fungus. If a particular type of leaf is found to be toxic to the fungus, the colony will no longer collect it. The ants feed on structures produced by the fungi called gongylidia. Symbiotic bacteria on the exterior surface of the ants produce antibiotics that kill bacteria introduced into the nest that may harm the fungi. 
Story: Bess and Dee were two entomologists. they were studying ants. Dee liked to learn more about indirect herbivory ants, while Bess learned all she could about all other ants. 
Question: Which person read more about scavenger ants?
[A]: Bess.


[Q]: Background Paragraph: Groundwater salinization compromises buffering properties. Vegetation clearance, along with irrigation, causes serious issues. Irrigation increases the water table and mobilizes salts, and vegetation clearance allows it to come in contact with water habitats and vegetation. This stresses species not adapted to high salinity. High levels of salinity reduces water uptake in plants, by causing stomatal closure, reducing photosynthesis. Forests undergo decline in areas of high salinity and shallow groundwater depths because these conditions make them more susceptible to droughts. Forests undergo decline in areas of high salinity and shallow groundwater depths making them more susceptible to droughts. 
Story: In the sixteenth century the State of Michigan had forests all over. But that has long been gone. 
Especially, in the state's northeast part the vegetation has been cleared in the twentieth century. 
Wooded areas were replaced by farm lands. All these farmlands were under heavy Irrigation. At one time, in the sixteenth century, plant species like elm and oak used to be plentiful. We still had some elms and oaks in the twentieth century, but they were not great many in number. 
Question: Which century saw northeast Michigan's water table increased, sixteenth century or twentieth century?
[A]:
twentieth century.