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: Many reactions take place in solution or in the gas phase, where the reactants are evenly dispersed throughout a homogeneous mixture. However, for reactions in which one of the reactants is a pure solid or liquid (meaning that this reactant is not already mixed together with any other reactants), reactivity only occurs at the surface, where particles of the solid or liquid reactant come into contact with particles of the other reactants. All of the molecules or ions in the interior of the pure substance will not be colliding with the other necessary reactants, so they are not really contributing to the overall rate of the reaction. However, increasing the surface area will increase the frequency of potentially reactive collisions, because more reactant particles will be in contact with the other necessary reactants. 
Story: Mike was preparing for his chemistry exam. To see the chemistry concepts in practice he conducted two tests, test A and test B. In test A he used two liquid reactants evenly dispersed, but in test B he used one liquid reactant and one solid reactant. He was surprised to see that two tests had very different results. 
Question: Which test would have higher rate of reaction, test A or test B?

A: test A.
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Q: Background Paragraph: Baker's yeast is the common name for the strains of yeast commonly used in baking bread and bakery products, serving as a leavening agent which causes the bread to rise (expand and become lighter and softer) by converting the fermentable sugars present in the dough into carbon dioxide and ethanol. Baker's yeast is of the species Saccharomyces cerevisiae,[1] and is the same species (but a different strain) as the kind commonly used in alcoholic fermentation, which is called brewer's yeast.[2] Baker's yeast is also a single-cell microorganism found on and around the human body. 
Story: the students used yeasts in two different experiments: they baked bread using baker's yeast, and made beer, using brewer's yeast. They learned a lot about sugars and chemistry. 
Question: Which yeast is better for bakery products?

A: baker's yeast.
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Q: Background Paragraph: Friction between the atmosphere and the Earth's surface causes a 20% reduction in the wind at the surface of the Earth.[10] Surface roughness also leads to significant variation of wind speeds. Over land, winds maximize at hill or mountain crests, while sheltering leads to lower wind speeds in valleys and lee slopes.[11] Compared to over water, maximum sustained winds over land average 8% lower.[12] More specifically, over a city or rough terrain, the wind gradient effect could cause a reduction of 40% to 50% of the geostrophic wind speed aloft; while over open water or ice, the reduction is between 10% and 30%.[8][13][14]. 
Story: The Johnson Family is planning a couple of excursions next week. On Wednesday they will be going to Tulsa Valley, and on Friday they are going to Albert's Peak, a small mountain in the area. Mr. Johnson has been wanting to fly some kites if there are some good wind conditions for doing so. He also wants to treat his family to a picnic and would like a more serene setting, with little to no wind to disrupt their picnic. 
Question: Will there be more or less wind on the Johnson Families' Wednesday trip than their Friday trip?

A:
less.
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