Question: Ted and Larry studied environmental sciences. They are learning about greenhouse gasses this week. Ted reads about carbon dioxide, while Larry reads about methane gas.  Which student read less about the most significant long-lived greenhouse gas in Earth's atmosphere?  Hint: Carbon dioxide is the most significant long-lived greenhouse gas in Earth's atmosphere. Since the Industrial Revolution anthropogenic emissions – primarily from use of fossil fuels and deforestation – have rapidly increased its concentration in the atmosphere, leading to global warming.  Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid.
Answer: Larry

Question: Tim and Jeb were both studying chemical engineering. At a certain point in time, Jeb started studying chemicals that are not harmful for the environment, while Tim started learning about chemicals that were once used, but now are known to be harmful for the environment.  Which student studied more about lead?  Hint: 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.
Answer: Tim

Question: Ricky, an entomologist, is observing an ant colony in his back yard. After some observation, he discovers that all the ants travel down one of two distinct paths in order to find food to bring back to the colony. After taking some measurements, Ricky sees that path A is approximately 100 meters in length, and path B is approximately 150 meters in length. Ricky is now trying to make some scientific conclusions based on these observations.  Which path will be marched over less frequently?  Hint: In the natural world, ants of some species (initially) wander randomly, and upon finding food return to their colony while laying down pheromone trails. If other ants find such a path, they are likely not to keep travelling at random, but instead to follow the trail, returning and reinforcing it if they eventually find food (see Ant communication).  Over time, however, the pheromone trail starts to evaporate, thus reducing its attractive strength. The more time it takes for an ant to travel down the path and back again, the more time the pheromones have to evaporate. A short path, by comparison, gets marched over more frequently, and thus the pheromone density becomes higher on shorter paths than longer ones. Pheromone evaporation also has the advantage of avoiding the convergence to a locally optimal solution. If there were no evaporation at all, the paths chosen by the first ants would tend to be excessively attractive to the following ones. In that case, the exploration of the solution space would be constrained. The influence of pheromone evaporation in real ant systems is unclear, but it is very important in artificial systems.[8]
Answer:
path B