crust

crust

CEFR: C1-C2 /crust/ [k.r.ah1.s.t]

The Earth's crust is its outer layer. Example sentence:

Example Sentences:
The continental crust is thought to have originated from the movement of magma when plate tectonics first formed billions of years ago.
The Earth consists of three main layers: the core, or the inner layer; the mantle, in the middle; and the crust, which includes the continents and ocean floor.

A crust is a hard layer of something, especially on top of a softeror wetter substance. Example sentence:

Example Sentences:
As the water evaporates, a crust of salt is left on the surface of the soil.