Q1: What process transforms energy in both fossil fuels and fuel cells?

Q2: Do fossil fuels or fuel cells produce less pollution in the process in the question above?

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)