#143 Plates

In geologic terms, a plate is a large, rigid slab of solid rock. The word tectonics comes from the Greek [1] "to build". Putting these two words together, we get the term plate tectonics, which [2] to how the Earth's surface is built of plates. The theory of plate tectonics [3] that the Earth's outermost layer is [4] into a dozen or more large and small plates that are moving [5] to one another.