Given a scientific question, generate a correct answer to it.

Example Input: What is defined as a repeating series of events that include growth, dna synthesis, and cell division?
Example Output: cell cycle

Example Input: Photoautotrophs and chemoautotrophs are two basic types of what?
Example Output: autotrophs

Example Input: Which pollution can cause lung cancer and can also make asthma and other diseases worse?
Example Output:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
air pollution

