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 Q]: Background Paragraph: A wood-decay fungus is any species of fungus that digests moist wood, causing it to rot. Some species of wood-decay fungi attack dead wood, such as brown rot, and some, such as Armillaria (honey fungus), are parasitic and colonize living trees. Excessive moisture above the fibre saturation point in wood is required for fungal colonization and proliferation.[1] Fungi that not only grow on wood but permeate its fibrous structure and actually cause decay, are called lignicolous fungi. In nature, this process causes the breakdown of complex molecules and leads to the return of nutrients to the soil.[2] Various lignicolous fungi consume wood in various ways; for example, some attack the carbohydrates in wood and some others decay lignin. The rate of decay of wooden materials in various climates can be estimated by empirical models.[3]. 
Story: Bob is a botanist. His interest is in different kinds of fungi. He went to Brazil last month to study fungi in 
the Amazon rain forest. First day he searched for fungi in a location with excessive moisture. Second day he searched for fungi in a location with no moisture. In all his search he found two specimens of fungi. Specimen A is a brown rot fungus, and specimen B is a honey fungus. 
Question: Would specimen A fungus live on dead woods or not live on dead woods?
[EX A]: live on dead woods.

[EX Q]: Background Paragraph: The lungs of mammals are unique in having alveoli . These are tiny, sac-like structures. Each alveolus is surrounded by a network of very small blood vessels (see Figure below ). Because there are millions of alveoli in each lung, they greatly increase the surface area for gas exchange between the lungs and bloodstream. Human lungs, for example, contain about 300 million alveoli. They give the lungs a total surface area for gas exchange of up to 90 square meters (968 square feet). That’s about as much surface area as one side of a volleyball court!. 
Story: Two groups of students studied Biology. Group One studied mammals, while Group Two studied birds. They focused on the respiratory system. 
Question: Which group of students learned more about alveoli?
[EX A]: One.

[EX Q]: Background Paragraph: In common everyday speech, speed of sound refers to the speed of sound waves in air. However, the speed of sound varies from substance to substance: sound travels most slowly in gases; it travels faster in liquids; and faster still in solids. For example, (as noted above), sound travels at 343 m/s in air; it travels at 1,480 m/s in water (4.3 times as fast as in air); and at 5,120 m/s in iron (about 15 times as fast as in air). In an exceptionally stiff material such as diamond, sound travels at 12,000 metres per second (27,000 mph);[1] (about 35 times as fast as in air) which is around the maximum speed that sound will travel under normal conditions. 
Story: A popular radio station was playing the classic rock songs. There was a radio in a car with a lot of obstacles between the station. There was a fire with a lot of smoke, a river, and a mountain. The man driving the car had a great time listening to the classics. 
Question: Where was the radio signal traveling the speediest: river or smoke?
[EX A]:
river.