Oort cloud: a spherical region that surrounds the solar system, that extends from the kuiper belt to almost halfway to the nearest star, and that contains billions of comets
Answer:
Earth can be divided into three main layers: the core, the mantle and the crust. Each of these layers can be further divided into two parts: the inner and outer core, the upper and lower mantle and the continental and oceanic crust. Both the inner and outer core are made up of mostly iron and a little bit of nickel.
Explanation:
It is called peristalsis movement.