Trenches form at sites where
a. one plate descends beneath another.
b. erosion cuts into the continental shelf.
c. two plates diverge under the sea.
d. the tops of undersea volcanoes collapse.

The process by which liquid water changes into water vapour is called what ?

Why might a single rock layer exhibit different types of sedimentary rocks within it? view available hint(s) why might a single rock layer exhibit different types of sedimentary rocks within it? such a rock layer, termed a facies, when traced laterally represents a variety of depositional environments that formed in a sequence over time. such a rock layer, termed a facies, when traced laterally represents a single depositional environment that formed over time. such a rock layer, termed a facies, when traced vertically represents a variety of depositional environments that formed at the same time across a broad area. such a rock layer, termed a facies, when traced laterally represents a variety of depositional environments that formed at the same time across a broad area. such a rock layer, termed a facies, when traced vertically represents a variety of depositional environments that formed in a sequence over time.

In africa what do they call a crop grown for direct sale and not for use?