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.

Ex Input:
Background Paragraph: As a young man, Bohr worked in Rutherford's lab in England. Because Rutherford's model was weak on the position of the electrons, Bohr focused on them. He hypothesized that electrons can move around the nucleus only at fixed distances from the nucleus based on the amount of energy they have. He called these fixed distances energy levels, or electron shells. He thought of them as concentric spheres, with the nucleus at the center of each sphere. In other words, the shells consisted of sphere within sphere within sphere. Furthermore, electrons with less energy would be found at lower energy levels, closer to the nucleus. Those with more energy would be found at higher energy levels, farther from the nucleus. Bohr also hypothesized that if an electron absorbed just the right amount of energy, it would jump to the next higher energy level. Conversely, if it lost the same amount of energy, it would jump back to its original energy level. However, an electron could never exist in between two energy levels. These ideas are illustrated in the Figure below .
Story: Greg was studying Bohr's model. He found it helpful to categorize different scenarios in the model. First, he labeled electron with higher energy as cat A, and electron with lower energy as cat B. Then he labeled electron that gained energy as cat C, and election that lost energy as cat D.
Question: Which energy level would cat A reside, higher energy level or lower energy level?

Ex Output:
higher energy level.

Ex Input:
Background Paragraph: Cancer is a disease that causes cells to divide out of control. Normally, the body has systems that prevent cells from dividing out of control. But in the case of cancer, these systems fail. Cancer is usually caused by mutations. Mutations are random errors in genes. Mutations that lead to cancer usually happen to genes that control the cell cycle. Because of the mutations, abnormal cells divide uncontrollably. This often leads to the development of a tumor. A tumor is a mass of abnormal tissue. As a tumor grows, it may harm normal tissues around it. Anything that can cause cancer is called a carcinogen . Carcinogens may be pathogens, chemicals, or radiation.
Story: A team of scientists studied two groups of mice. Group C was exposed to carcinogens, while group N was not.
Question: Which group of mice had fewer abnormal cells divide uncontrollably?

Ex Output:
group N.

Ex Input:
Background Paragraph: Geologists study earthquake waves to "see" Earth's interior. Waves of energy radiate out from an earthquake's focus. These waves are called seismic waves ( Figure below ). Seismic waves go different speeds through different materials. They change speed when they go from one type of material to another. This causes them to bend. Some seismic waves do not travel through liquids or gases. They just stop. Scientists use information from seismic waves to understand what makes up the Earth's interior.
Story: Mary is studying the seismic waves of a recent earthquake from 2 locations around its focus. She notes at point A the waves are easily detectable. at point B the waves are unable to be read at all, as if they just stopped.
Question: Given Mary decides to check the readings for two other locations, points C and D, and notices the waves at D are slower, will the areas underground at points C and D be made of the same materials or different materials?

Ex Output:
different.