instruction:
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.
question:
Background Paragraph: The example of someone having a positive experience with a drug is easy to see how drug dependence and the law of effect works. The tolerance for a drug goes up as one continues to use it after having a positive experience with a certain amount the first time.[38] It will take more and more to get that same feeling. This is when the controlled substance in an experiment would have to be modified and the experiment would really begin. The law of work for psychologist B. F. Skinner almost half a century later on the principles of operant conditioning, "a learning process by which the effect, or consequence, of a response influences the future rate of production of that response.[39]. 
Story: The cocaine club met to discuss their experiences. They all said they always had a great experience using cocaine and used the same amount each time. They told how many times they used cocaine. Mary used it 2 times, Patricia used it 3 times, Linda used it 5 times, Barbara used it 10 times, Elizabeth used it 15 times, Jennifer used it 20 times, and Maria used it 30 times. 
Question: Who has a higher tolerance for cocaine: Jennifer or Linda?
answer:
Jennifer.


question:
Background Paragraph: Sometimes muscles and tendons get injured when a person starts doing an activity before they have warmed up properly. A warm up is a slow increase in the intensity of a physical activity that prepares muscles for an activity. Warming up increases the blood flow to the muscles and increases the heart rate. Warmed-up muscles and tendons are less likely to get injured. For example, before running or playing soccer, a person might jog slowly to warm muscles and increase their heart rate. Even elite athletes need to warm up ( Figure below ). 
Story: Two teams of athletes were attending a competition. Brown team arrived in time and started their warm up, but Green team arrived late and skipped their warm up so they experienced some people getting injured. 
Question: Which team experienced more tendon injuries?
answer:
Green.


question:
Background Paragraph: Since AM fungi are biotrophic, they are dependent on plants for the growth of their hyphal networks. Growing a cover crop extends the time for AM growth into the autumn, winter, and spring. Promotion of hyphal growth creates a more extensive hyphal network. The mycorrhizal colonization increase found in cover crops systems may be largely attributed to an increase in the extraradical hyphal network that can colonize the roots of the new crop (Boswell et al. 1998). The extraradical mycelia are able to survive the winter, providing rapid spring colonization and early season symbiosis (McGonigle and Miller 1999). This early symbiosis allows plants to tap into the well-established hyphal network and be supplied with adequate phosphorus nutrition during early growth, which greatly improves the crop yield. 
Story: Two farms used AM fungi for the plants. Brown farm also decided to grow cover crops on those parcels of land to help mycorrhizal growth. Orange farm didn't grow cover crops. 
Question: Which farm increased the extraradical hyphal network that can colonize the roots of the new crop?
answer:

Brown.