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.

Background Paragraph: Shown in the Figure below is a cylinder of gas on the left that is at room temperature (300 K). On the right, the cylinder has been heated until the Kelvin temperature has doubled to 600 K. The kinetic energy of the gas molecules increases, so collisions with the walls of the container are now more forceful than they were before. As a result, the pressure of the gas doubles. Decreasing the temperature would have the opposite effect, and the pressure of an enclosed gas would decrease.
Story: In a laboratory, Marcus is working with two identical containers of the same amount of gas inside them. For his next experiment, he needs these containers to be different temperatures. He takes container X and puts it in the refrigerator, and he leaves container Y out on the table. One hour later, he comes back and takes container X out of the refrigerator so he can now begin his experiment.
Question: Which container has more kinetic energy?
container Y.

Background Paragraph: Bernoulli's law explains how the wings of both airplanes and birds create lift that allows flight (see Figure below ). The shape of the wings causes air to flow more quickly and air pressure to be lower above the wings than below them. This allows the wings to lift the plane or bird above the ground against the pull of gravity. A spoiler on a race car, like the one in Figure below , works in the opposite way. Its shape causes air to flow more slowly and air pressure to be greater above the spoiler than below it. As a result, air pressure pushes the car downward, giving its wheels better traction on the track.
Story: Rob is experimenting with how air pressure works. To that end, he has designed two tests. In the first test the air flow works as it would in an airplane wing. He labels it as case A. In the second test the air flow works as it would in a race car spoiler. He labels it as case B. He is surprised to see that air flow behaves differently in different situations.
Question: Would case A have faster or slower air flow above it than case B?
faster.

Background Paragraph: Prokaryotes have a different way to increase genetic variation. It's called genetic transfer or bacterial conjugation . It can occur in two ways. One way is when cells "grab" stray pieces of DNA from their environment. The other way is when cells directly exchange DNA (usually plasmids) with other cells. For example, as shown in Figure below , the donor cell makes a structure called an F pilus , or sex pilus. The F pilus attaches one cell to another cell. The membranes of the two cells merge and genetic material, usually a plasmid , moves into the recipient cell. Genetic transfer makes bacteria very useful in biotechnology. It can be used to create bacterial cells that carry new genes.
Story: Two researches studied living organisms, Joe studied eukaryotes, while Bill studied prokaryotes. They were fascinated by genetic variation.
Question: Which researcher observed more cells directly exchange DNA (usually plasmids) with other cells?
Bill.