Which statement best describes how railroads changed industrial practices?

railroads connected inland cities to seaports
railroads made automobiles obsolete
railroads made traveling safer
railroads could go over mountains

name two ways organisms join a population and two ways organisms leave a population. two ways organisms join a population are birth rate and immigration. two ways they leave are death rate and emigration.

explanation:

- "the most famous structure by far at saqqara is djoser's step pyramid. dating from the 3rd dynasty (2667—2448 bc), it was the first all-stone complex ever built on earth."

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