Which of these natural phenomena is least likely to cause the formation of a large plain valley between two mountains, in a very short time?

Seed plants that lived during the carboniferous impact life on earth today because a. they are the ancestors of all plant life on earth. b. their remains formed coal, which is an important resource. c. they produced fossils that are used to date many geologic events. d. their presence caused oxygen levels to drop, allowing animals to evolve.

Why are shark population in decline worldwide?

Distance that lewis and clark traveled from st. louis to ft. clatsop near the pacific ocean.