Problem: In exercises such as weight lifting, skeletal muscle contracts against a resisting force (see Figure below ). Using skeletal muscle in this way increases its size and strength. In exercises such as running, the cardiac muscle contracts faster and the heart pumps more blood. Using cardiac muscle in this way increases its strength and efficiency. Continued exercise is necessary to maintain bigger, stronger muscles. If you don't use a muscle, it will get smaller and weakerso use it or lose it. Two groups of soldiers started different training programs. Blue group did weight training for 3 months, while Brown group ran 3 miles a day for three months. The Captain observed different results on each group. Which group increased the efficiency of their cardiac muscle?

A: Brown

Problem: Greenhouse Effect: The solar energy reaching the surface of the Earth is concentrated in short wavelengths, which can easily penetrate the greenhouse gases, such as carbon dioxide and methane. The Earth, however, is cooler than the sun and it radiates its heat in the form of energy in the far infrared range. These longer wavelengths are partially absorbed by the greenhouse gases and some of the solar heat is returned to Earth. At a certain temperature these processes are in equilibrium and the surface temperature of the Earth is stable. However, if more greenhouse gases are put in the atmosphere the amount of trapped terrestrial radiation increases, leading to an increase in global temperature. John was interested in climate change issues. To that end, he studied two imaginary situations, case A and case B. In case A, there would not be excessive greenhouse gases in the atmosphere. On the contrary, in case B, the amount of greenhouse gases in the atmosphere would increase dramatically. John realized that the amount of greenhouse gases in the atmosphere has many practical implications. In which case the surface temperature of the Earth would be higher, case A or case B?

A: case B

Problem: Many chemicals that were once commonly used were later found out to be harmful to the environment , to human health, or both. The element lead was once a common additive to gasoline and to paint. Plumbing pipes were once typically made of lead. Only since the 1970s has the danger of lead become apparent. It causes brain damage and small children (who often chewed on objects painted with lead-based paint) are particularly susceptible. The use of lead in gasoline, paint, and plumbing pipes is now banned and new materials are being developed to replace the hazardous lead components. Hank and Brian both grew up in the 1950s. They enjoyed playing with toys, but they each had a personal favorite. Hank's favorite toy as a child was his wooden baseball bat. Brian's favorite toy was a metal model car set that came with paint a child could use to paint the car however they wanted. They both have very fond memories of their childhood and Hank still has the baseball bat and his grandchildren now use it when they visit him. Which child was more likely exposed to dangerous amounts of lead?

A: Brian

Problem: Raising the temperature of a chemical reaction usually results in a higher rate of reaction. When the reactant particles are heated, they move faster and faster. This results in a greater frequency of collisions. A more important effect of the temperature increase is that the collisions occur with a greater force and are thus more likely to surmount the activation energy barrier and go on to form products. Increasing the temperature of a reaction increases the number of effective collisions between reacting particles, so the reaction rate increases. Two colleagues read about types of chemical reactions. Sean studied about the influence of temperature on chemical reactions. Gabe studied about other influencing factors. Which student read less about the activation energy barrier?

A:
Gabe