Briefly describe the strategy of island hopping during the war in the pacific

Describe the technology advancements that lead to explorers being able to sail great distances. [[ps: doesn't explain where. i am only speculating it's in europe.

What form of government is powers of states? first letter of the answer is r.

What event started the space race and made americans feel their security was threatened a.) alan shepard's suborbital flight. b.) the launch of sputnik c.) the launch of explorer d.) the cuban missle crisis