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.
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Question: Background Paragraph: During the 1670s, the Dutch tradesman Antony van Leeuwenhoek, shown in Figure below , used microscopes to observe many microbes and body cells. Leeuwenhoek developed an interest in microscopy and ground his own lenses to make simple microscopes. Leeuwenhoek was so good at making lenses that his simple microscopes were able to magnify much more clearly than the compound microscopes of his day. His microscope's increased ability to magnify over 200x is comparable to a modern compound light microscope. Compound microscopes , which are microscopes that use more than one lens, had been invented around 1595 by Zacharias Jansen, a Dutch spectacle-maker. Several people, including Robert Hooke, had built compound microscopes and were making important discoveries with them during Leeuwenhoek’s time. 
Story: John is interested in the history of science. He went to a science museum to learn more about microscopes. First he saw a Leeuwenhoek microscope, which was labeled as item A, then he saw a compound microscope of Leeuwenhoek's time, which was labeled as item B. At the very end of his museum tour he saw a modern compound light microscope, which was labeled as item C. 
Question: Which microscope could magnify less clearly, item A or item B?

Answer: item B.


Question: Background Paragraph: The ionization energies of the representative elements generally decrease from top to bottom within a group. This trend is explained by the increase in size of the atoms within a group. The valence electron that is being removed is further from the nucleus in the case of a larger atom. The attractive force between the valence electron and the nucleus weakens as the distance between them increases and as the shielding effect increases, resulting in a lower ionization energy for the larger atoms within a group. Although the nucl. 
Story: Rob is learning about ionization. He looks at a specific group of elements from top to bottom to figure out thier ionization energy. 
Question: Which element will have a higher shielding effect, the top element or the bottom element?

Answer: bottom element.


Question: Background Paragraph: Vapor pressure is a measure of the pressure exerted by a gas above a liquid in a sealed container. While viscosity and surface tension increase as the strength of intermolecular forces increase, vapor pressure decreases . This is because the stronger the intermolecular forces are, the harder it is for liquid molecules to escape into the gas phase. Vapor pressure a measure of how much of a substance is in the gas phase when that substance is at equilibrium; that is, the number of molecules in the gas and liquid phases are not changing. The more molecules that are able to escape into the gas phase, the higher the vapor pressure. Vapor pressure is also proportional to temperature. As temperature increases, vapor pressure also increases. 
Story: As a part of his engineering job Keith is measuring the vapor pressure of two locomotives, engine A and engine B. 
Engine A has a high vapor pressure, but engine B has a low vapor pressure. He noticed that to increase the speed of the engines he needed to increase the vapor pressure. 
Question: In which engine more liquid molecules would turn into gas phase, engine A or engine B?

Answer:
engine A.