Which of the following is one way to prevent the corrosion of iron?
a. add carbon to the iron. b. paint exposed iron parts with protective paint. c. let the iron develop a natural coat of carbonate. d. protect the iron from polluted air

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)