Answer:
biosphere
Explanation:
Earth Spheres. Everything in Earth's system can be placed into one of four major subsystems: land, water, living things, or air. These four subsystems are called “spheres.” Specifically, they are the lithosphere (land), hydrosphere (water), biosphere (living things), and atmosphere (air).
Answer:
b
Explanation:
because of oil and rare materials at the floor of the ocean
Answer: B. The smallest part of an atom
Explanation:
Electrons are the smallest of the three particles that make up atoms. Electrons are found in shells or orbitals that surround the nucleus of an atom. Protons and neutrons are found in the nucleus. They group together in the center of the atom.
Max Knott and Ernst Ruska invented the electron microscope