Problem: Bob has just graduated from medical school. He went on to serve his community. Especially he is interested in treating children. One day he saw two children, child M and child N, and found child M is infected with Acute Hepatitis B while child N is infected with Chronic Hepatitis B. Next day he saw two other children, child O and child P. Child O was younger, but child P was older. Did child N's illness occur within six months of exposure or the virus remained in his body? Hint: Hepatitis B is a contagious virus that affects the liver, infection can last from a few weeks to a serious lifelong illness. Two different types of infection exist for this disease, "acute" and "chronic." Acute Hepatitis B is a short term illness that occurs within 6 months of exposure, Chronic Hepatitis B is long term and happens when the virus remains in the body. The younger the child is, the greater their chance of developing a chronic infection and this risk goes down as the child gets older. Approximately 90% of infected infants will develop a chronic infection.[3]

A: virus remained in his body

Problem: Two teams of runners were training for a 10k. Team Y jogged early in the morning when the weather was cool. Team X started their training in the heat so many team members had problems sweating. Which team had fewer people that experienced fatigue? Hint: Millions of people in the world jog for exercise. For the most part, jogging can be a healthy way to stay fit. However, problems can also develop for those who jog in the heat. Excessive sweating can lead to electrolyte loss that could be life-threatening. Early symptoms of electrolyte deficiency can include nausea, fatugue, and dizziness. If not treated, individuals can experience muscle weakness and increased heart rate (which could lead to a heart attack). Many sports drinks can be consumed to restore electrolytes quickly in the body.

A: Team Y

Problem: Tom and Jerry were two 50-year-olds which went to high-school together. They recently met and discussed their health problems over coffee. Tom had hypertension and the doc told him to change his diet. Which friend didn't have to start drinking skim milk? Hint: Hypertension , which is also called "high blood pressure," occurs when a person's blood pressure is always high. Hypertension is said to be present when a person's systolic blood pressure is always 140 or higher, and/or if the person's diastolic blood pressure is always 90 or higher. Having hypertension increases a person's chance for developing heart disease, having a stroke, or suffering from other serious cardiovascular diseases. Hypertension often does not have any symptoms, so a person may not know that he or she has high blood pressure. For this reason, hypertension is often called the "silent killer." Treatments for hypertension include diet changes, exercise, and medication. Foods thought to lower blood pressure include skim milk, spinach, beans, bananas and dark chocolate.

A: Jerry

Problem: Dorothy is riding an elevator. The elevator has bristles running up the side of the tracks so her jeans are rubbing against them. When he gets to the top of the elevator she accidentally brushes a piece of metal and gets a small electric shock from it. Will objects moving from one object to anothr cause the first to become positively charged or negatively charged? Hint: Electrons can be removed from some objects using friction, simply by rubbing one substance against another substance. There are many examples of objects becoming charged by friction, including a rubber comb through hair, and a balloon on a sweater. In both these instances, the electrons move from the second object to the first, causing the first object to become negatively charged and the second one positively charged. Friction between the tires on a moving car and the road cause the tires to become charged, and wind causes friction between clouds and air which causes clouds to become charged and can result in tremendous bolts of lightning.

A:
positively