Problem: Hydrologists studied two samples of rain water. Jim studied an acid rain sample from a nearby city, and Dan studied a sample of water from another town. Which hydrologist didn't learn that acid rain falls in freshwater habitats?

A: Dan

Problem: Scientists are finding more and more evidences of water in the outer space. Earth has mostly liquid water. But that's not the case with other celestial objects. Venus has some water, but it is in gaseous state. On the other hand, water in Jupiter's moon Europa is in frozen state. In Europa would the state of water in higher or lower denstiy than in Earth?

A: lower

Problem: 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. Would case A have higher or lower air pressure above it than case B?

A: lower

Problem: Mike is a biochemist, working for a science lab. Today, he has two organisms to investigate, organism A and organism B. He notices that organism A has enzymes, but organism B lacks enzymes. He needs to figure out how these conditions would affect the organisms. Under normal conditions, in which organism the chemical reactions would be less plausible, organism A or organism B?

A:
organism B