Problem: Two pedologists studied different types of soil. Yun studied forest soils, while Jian studied grassland soil. They were both very surprised with they findings. Which scientist read less about tree leaves falling on the forest floor?

A: Jian

Problem: When comparing village A from ten thousand years ago to village B from today, we reached the conclusion that today's villagers release much more carbon into the atmosphere by their activities. Which village cut more forests?

A: village B

Problem: The marine biologists studied two areas of the Black Sea. Area A, situated at the mouth of the Danube River, which presented high levels of water stratification, because of the fresh water discharged by the river; and area B, situated 35 miles south, where the water was less stratified and more oxygenated. Which of the two areas had more salinity?

A: area B

Problem: Danny started weight lifting two years ago, he wanted to be bigger. His brother Arnie preferred athletic competitions such as running, so he became a runner. Which brother increased the efficiency of his cardiac muscle?

A:
Arnie