What dependent variables can be recorded in this lab setup? How does the voltmeter work? How does the ammeter work?

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.

On the map below, which of the following rivers is identified by blue? the huang he river the yangtze river the han river the naktong river

The meseta in spain is a a. navigable river b. castle c. coastal plain d.plateau