Problem: Two researchers studied air quality over the North Pole, and over Antarctica. Dan was more fond of the south pole, so he studied Antarctica, while Colt liked reading about the North Pole. Which researcher learned more about aerosol sprays?

A: Dan

Problem: Two students studied the atmosphere of Earth and other planets from our solar system. Zack learned about Earth's atmosphere, while Ken learned about the atmospheric conditions on planet Venus. Which student learned less about corrosive sulfuric acid?

A: Zack

Problem: In the sixteenth century the State of Michigan had forests all over. But that has long been gone. Especially, in the state's northeast part the vegetation has been cleared in the twentieth century. Wooded areas were replaced by farm lands. All these farmlands were under heavy Irrigation. At one time, in the sixteenth century, plant species like elm and oak used to be plentiful. We still had some elms and oaks in the twentieth century, but they were not great many in number. Was the mobilized salts at increased or decreased level in northeast Michigan in the sixteenth century?

A: decreased level

Problem: People in Iran used extensive grazing, fell most of their trees so they have lots of problems with desertification. Iraq took a more mindful approach to land use, they preserved native species, planted trees and didn't overgraze the land. Which country lost more vegetation and wildlife?

A:
Iran