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.
Melanin is a pigment that is produced by cells known as melanocytes in the skin of most animals, including humans. ...
Answer:
Answer would be no.
B)carbon, hydrogen and oxygen
Answer:
The molecules of the substances must be touching.
Explanation:
Conduction is the process by which heat energy is transmitted through collisions between neighboring atoms or molecules
