TASK DEFINITION: In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.
PROBLEM: Question: What type of hydrocarbon is coal? Answer: solid

SOLUTION: Solid type of hydrocarbon is coal.

PROBLEM: Question: What system consists of neurons that carry signals to skeletal muscles? Answer: motor system

SOLUTION: The motor system consists of neurons that carry signals to skeletal muscles.

PROBLEM: Question: Community interactions are important factors in what? Answer: natural selection

SOLUTION:
Community interactions are important factors in natural selection.