Answer:
Oxygen or Minerals or Sugars (Oxygen is the most relevant one)
Explanation:
To survive, every cell must have a constant supply of vital substances such as sugar, minerals, and oxygen, and dispose of waste products, all carried back and forth by the blood cells. Without these substances, cells would die in a very short period of time.
Sunspots are temporary phenomena on the Sun's photosphere that appear as spots darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic field flux that inhibit convection. Sunspots usually appear in pairs of opposite magnetic polarity.
Explanation:
Un estimulo es cualquier cambio que es capaz de producir una respuesta por parte del organismo. Los receptores son estructuras muy especializadas capaces de percibir los estímulos y convertirlos en impulsos nerviosos
I think the answer to this is abyssal plane
