Placer mining involves to extract minerals. a. removing the top layer of earth
b. tunneling under the earth
c. dredging sediments from the water bottom
d. none of the above

And give a detailed description! scientist observes the boundary between two tectonic plates for a decade and finds that no new volcanoes have formed over the course of her investigation. does this result support the theory of plate tectonics? why or why not?

What are the two main phases of a cell cycle

How much time has elapsed from the very beginning of "the memior of the conquistador bernal diaz del castillo" to the end? a. castillo's whole life b. a quarter of an hour c. a few weeks d. a decade