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

Example Input: What is the general shape of centrioles?
Example Output: rod

Example Input: A black solid by itself, this element is incredibly important because of what it makes when it combines with many other elements, including oxygen?
Example Output: carbon

Example Input: What is a hydrocarbon in which the carbon chain joins to itself in a ring?
Example Output:
cyclic hydrocarbon