Tectonic plates are large segments of the Earth's crust that move slowly. Suppose one such plate has an average speed of 3.0 cm per year. (a) What distance does it move in 90 seconds at this speed

Which of the following is true about fossils? a. the relative age of fossils cannot be determined from their position in sedimentary layers. b. fossils found in lower layers of sedimentary rock are as old as fossils found in upper layers of sedimentary rock. c. fossils found in upper layers of sedimentary rock are older than fossils found in lower layers of sedimentary rock. d. fossils found in lower layers of sedimentary rock are older than fossils found in upper layers of sedimentary rock.

Because its government strictly controls its economy, north korea has a economy. a. command b. mixed c. traditional d. free market

An igneous rock that contains mostly pyroxene and olivine has what type of composistion