[Q]: Given the background: Naturally occurring uranium is composed almost entirely of two isotopes, uranium-238 (99%) and uranium-235 (1%). It is the uranium-235 that is fissionable (will undergo fission) and therefore, this is the uranium isotope than can be used for fuel in a nuclear reactor. For uranium to be used as fuel, the percent of uranium-235 must be increased to at least 3%. Uranium in which the U-235 content is more than 1% is called enriched uranium. Somehow, the two isotopes must be separated so that enriched uranium is available for use as fuel. Separating the isotope by chemical means (chemical reactions) is not successful because the isotopes have exactly the same chemistry. The only essential difference between U-238 and U-235 is their atomic masses; as a result, the two isotopes are separated by a physical means that takes advantage of the difference in mass. and the situation: John is a nuclear scientist who works at the Fermi lab. Today, in front of him he has four samples, sample A, sample B, sample C, and sample D. Sample A is the naturally occurring uranium. Sample B is enriched uranium. Sample C is the U-238, and sample D is the U-235. He needs to figure out how to best use them. Answer the following question: Which sample would less likely be used as fuel, sample C or sample D?
****
[A]: sample C

input: Please answer the following: Given the background: Greenhouse Effect: The solar energy reaching the surface of the Earth is concentrated in short wavelengths, which can easily penetrate the greenhouse gases, such as carbon dioxide and methane. The Earth, however, is cooler than the sun and it radiates its heat in the form of energy in the far infrared range. These longer wavelengths are partially absorbed by the greenhouse gases and some of the solar heat is returned to Earth. At a certain temperature these processes are in equilibrium and the surface temperature of the Earth is stable. However, if more greenhouse gases are put in the atmosphere the amount of trapped terrestrial radiation increases, leading to an increase in global temperature. and the situation: Two friends liked studying about the Earth's atmosphere. Vick studied more about the troposphere, while Frank studied more about the Greenhouse Effect. Answer the following question: Which friend studied more about short wavelength solar energy?
++++++++++
output: Frank

Please answer this: Given the background: Cholesterol has been implicated in heart disease for decades. Atherosclerosis is a disorder of the arteries in which cholesterol and other materials are deposited on the interior of the arterial wall. These deposits lead to the formation of plaques that can restrict or even block the flow of blood through these blood vessels (see Figure below ). A decrease in the flow of blood can lead to high blood pressure and a lowered oxygen supply to the heart muscle. A complete blockage of blood flow to parts of the heart (a heart attack) can cause significant damage due to oxygen deprivation, in some cases leading to death. and the situation: Brad and Dale went to the doctor for a check up. Brad did some blood tests and found out he has very high cholesterol levels, while his partner Dale had normal cholesterol levels, and was very healthy. Brad got scared and started worrying. Answer the following question: Which friend was more at risk for heart disease?
++++++++
Answer: Brad

Problem: Given the background: Any unused energy in foodwhether it comes from carbohydrates, proteins, or lipidsis stored in the body as fat. An extra 3,500 Calories of energy results in the storage of almost half a kilogram (1 pound) of stored body fat. People who consistently consume more food energy then they need may become obese. Obesity occurs when the body mass index is 30.0 kg/m 2 or greater. Body mass index (BMI) is an estimate of the fat content of the body. It is calculated by dividing a person's weight (in kilograms) by the square of the person's height (in meters). Obesity increases the risk of health problems such as type 2 diabetes and hypertension. and the situation: Two brothers had very different diets. Vick would constantly eat foods high in fat and would frequently overeat. Zack on the other hand, had a higher metabolic rate, a faster metabolism, and he would eat the correct amount of calories. Answer the following question: Which brother had a lower chance of developing type 2 diabetes?

A: Zack

Problem: Given the question: Given the background: Air pollution is harmful to human beings and other living things. About 22 million people die from air pollution each year. Breathing polluted air increases the risk of developing lung diseases such as asthma and lung cancer. Breathing bad air also increases the chances of dying from other diseases. Children are most likely to be affected by air pollution. That's because their lungs are still developing and growing. Children also take in more air for their size than adults do. Some air pollutants damage the environment as well as the health of living things. The type of damage depends on the pollutant. Air pollution can also harm the environment. and the situation: Sarah and Sophie are sisters living in two different cities. Sarah lives in a very rural area with hardly any air pollution. Sophie lives in a heavily industrialized urban area with many factories and people driving cars to their destinations. This all leads to Sophie's city having a large amount of pollution going into the atmosphere. Answer the following question: Who is more susceptible to other diseases?
++++++++++++++++++++++++++++++++
The answer is:
Sophie

Problem: Given the background: The Keystone XL Pipeline would transport oil from the oil sands in Alberta, Canada. The oil would travel into the United States. In the U.S. it would be refined. The pipeline is controversial. A leak could cause damage to wildlife habitat. A leak could also release enough oil to contaminate the Ogallala Aquifer. The Aquifer is crucial to agriculture and urban development in the Midwestern U.S. When burned, the fuel from the oil sands would increase pollutants. Greenhouse gases into the atmosphere would increase. The future of the pipeline is currently on hold. and the situation: Lawmakers were debating the pros and cons of Keystone XL Pipeline. One group of lawmakers proposed that the pipeline be constructed. They put their proposal in proposal A. The rival group of lawmakers proposed that the pipeline should not be build. They put their proposal in proposal B. Lawmakers would now have to choose one of the proposals. Answer the following question: Which proposal might not contaminate the aquifer, proposal A or proposal B?

A:
proposal B