Given a scientific passage and an answer, generate a question for the given answer.

[EX Q]: Passage: Figure 12.7 Statues made from carbonate compounds such as limestone and marble typically weather slowly over time due to the actions of water, and thermal expansion and contraction. However, pollutants like sulfur dioxide can accelerate weathering. As the concentration of air pollutants increases, deterioration of limestone occurs more rapidly. (credit: James P Fisher III). Answer: air pollutants
[EX A]: Deterioration of limestone occurs more rapidly as the concentration of what increases?

[EX Q]: Passage: Did you ever have a picnic ruined by a surprise rainstorm? People often complain when the weather forecast is wrong. But in fact, weather forecasts today are much more accurate than they were just 20 years ago. Scientists who study and forecast the weather are called meteorologists . How do they predict the weather?. Answer: meteorologists
[EX A]: What do we call scientists who study and forecast the weather?

[EX Q]: Passage: Many of the problems with fossil fuels are worse for coal than for oil or natural gas. Burning coal releases more carbon dioxide than either oil or natural gas. Yet coal is the most common fossil fuel, so we continue to burn large amounts of it. That makes coal the biggest contributor to global warming. Answer: coal
[EX A]:
What is the most common fossil fuel?