The most widely accepted theory of planetary formation, known as the nebular hypothesis, maintains that 4.6 billion years ago, the Solar System formed from the gravitational collapse of a giant molecular cloud which was light years across.
Answer:
1. They usually host three or more ecosystems where animals can’t live.
4. They usually host one ecosystem with a variety of plants
Explanation:
A mountain ecosystem has more than one ecosystem. This is mainly due to the diversity of climate that this environment promotes. Due to its proximity to the ocean, slope and elevation, the mountain ecosystem promotes different areas that create different ecosystems, some more humid and others drier.
In this environment there is usually a wide variety of plants, but not animals.
A and d I believe are correct
The Inca used those metals to decorate their palaces and had silverware, cups and dishes made of them.
Of course, only royalty had that.
Market economies are based on market forces like supply and demand. Mixed economies fall in the middle of market and command economies (where economic choices are governed by some central entity usually the government). The former Soviet Union (USSR) is an example of a command economy where economic choices (what to buy, sell and produce) where made by the government. If Australia is becoming more of a market economy and less of a mixed economy, fewer decisions are made by the government. Here's a diagram of two major types of economies:
Command Economy <-------------- Mixed Economy --------> Market Economy
(Government makes the decisions) (A little of both) (Individuals decide)
