Problem: You are given a new situation: Jacob recently contracted the HIV virus and is going to his first support meeting. While there, he meets Dan and strikes up a conversation with him. Dan says that he has had HIV for over a decade at this point and has learned ways to live with it. He is able to give Jacob some good advice on how to handle things and Jacob is very grateful to have someone to talk with. and a hint : As time passes, the number of HIV copies keeps increasing, while the number of helper T cells keeps decreasing. The graph in Figure below shows how the number of T cells typically declines over a period of many years following the initial HIV infection. As the number of T cells decreases, so does the ability of the immune system to defend the body. As a result, an HIV-infected person develops frequent infections. Medicines can slow down the virus but not get rid of it, so there is no cure at present for HIV infections or AIDS. There also is no vaccine to immunize people against HIV infection, but scientists are working to develop one. Please answer this question : Which person's body will struggle more to defend from the HIV infection?

A: Dan

Problem: You are given a new situation: Steve and Chris sit down at a new cafe that just opened up in town after hearing rave reviews of it at work. They look at the menus trying to decide what to order when a waiter shows up and asks if they would like anything to drink. Steve says he would like a glass of water that has molecules far apart. Chris orders water with molecules closer together. The waiter looks at them with a rather confused look and asks them to please elaborate. and a hint : Liquid water is a fluid. The hydrogen bonds in liquid water constantly break and reform as the water molecules tumble past one another. As water cools, its molecular motion slows and the molecules move gradually closer to one another. The density of any liquid increases as its temperature decreases. For most liquids, this continues as the liquid freezes and the solid state is denser than the liquid state. However, water behaves differently. It actually reaches its highest density at about 4C. Please answer this question : Who ordered warmer water?

A: Steve

Problem: You are given a new situation: Bob works for the local electric power company. Part of is job involves checking the generators and transformers. His work schedule allows him to work on the generator tagged as gen A only on Mondays, and the transformer tagged as tran B only on Tuesdays. and a hint : Two important devices depend on electromagnetic induction: electric generators and electric transformers. Both devices play critical roles in producing and regulating the electric current we depend on in our daily lives. Electric generators use electromagnetic induction to change kinetic energy to electrical energy. They produce electricity in power plants. Electric transformers use electromagnetic induction to change the voltage of electric current. Some transformers increase voltage and other decrease voltage. Please answer this question : Which one would most likely be located in a power plant, gen A or tran B?

A: gen A

Problem: You are given a new situation: 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. and a hint : 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 . Please answer this question : Would cat D Jump to higher level or go to lower level?

A:
go to lower level