How much salt is in a cup of ocean water

Ineed asap i will give 30 pointsps: the last word says splits

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.

The mantle is made up of which structural zones?