Problem: Ben and Andy researched significant greenhouse gasses in Earth's atmosphere. Andy researched more about carbon dioxide, while Ben researched methane gas. Which researcher studied the most significant long-lived greenhouse gas in Earth's atmosphere?

A: Andy

Problem: Keith was playing a simulation game. In the game he could travel around the Sun in the future. He started the game in present time, which was denoted as time A. Then he traveled 5.4 billion years into the future, which was denoted as time B. Finally, he reached 7.5 billion years into the future, which was denoted as time C. He was amazed to find how the Sun would change over time. Would the Sun's core be hotter or cooler in time B than in time A?

A: hotter

Problem: A team of scientists studied two groups of mice. Group C was exposed to carcinogens, while group N was not. Which group of mice had more cells to divide out of control?

A: Group C

Problem: Two countries were neighbors, separated by a mountain range. Ghana used fossil fuels to produce energy, but one of the consequences of that was increased air pollution and acid rain. Brunei was a country inhabited by nature lovers and tree huggers, so they were very protective of their environment. Which country had smaller amounts of low pH precipitation in the forests?

A:
Brunei