The outermost region of a planet's atmosphere.
Answer:
An open circuit is one where the continuity has been broken by an interruption in the path for current to flow. A closed circuit is one that is complete, with good continuity throughout.
Explanation:
For instance, a simple light switch opens and closes the circuit that connects a light to a power source. When you build a circuit, it's a good idea to disconnect the battery or other power source when the circuit is not in use.
Quaternary- Cenozoic era
Karoo - Paleozoic era
Andean-Saharan - Paleozoic era
Cryogenian - Neoproterozoic era
Huronian - <span>Paleoproterozoic era</span>
Mountain range or hill range is a series of mountains or hills ranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have arisen from the same cause, usually an orogen