Can you help me with this please thanks:)

How did the russian revolution impact world war i? a) the russians required the allied powers to come to their aid and defeat the radical groups. b) the russians pulled out from the war, enabling the germans to focus on the western front. c) the russians created new technological advancements that were used by the allied powers to win. d) the russians created a new communist government that aligned with the central powers instead.

Who was the first explorer to sail all the way down the mississippi river

What is the meaning of the phrase “bear ’t”? what word is left out between the words but and few?