Answer:
Oil
Explanation:
Since, unlike oil, source like wind, solar, water etc. come naturally we don't and can't replace them but when the viscosity in oil has been used up it must be change to allow the proper functioning of the machine.
Answer:
Water
Explanation:
Water is a renewable energy source used to generate electricity. A place where this happens at is dams.
According to the U.S. Geological Survey, most of that three percent is inaccessible. Over 68 percent of the fresh water on Earth is found in icecaps and glaciers, and just over 30 percent is found in ground water. Only about 0.3 percent of our fresh water is found in the surface water of lakes, rivers, and swamps. The use for the water in the world is for household drinking water. The ocean stores about 97 percent of the Earth's water; the remaining three percent is stored in glaciers and ice, below the ground, in rivers and lakes. Of the world's total water supply of about 332 million cubic miles of water, about 97 percent is stored in the ocean.
Hope this helps!
The answer is osteoclasts
