Definite article is used before a noun (person place or thing) to indicate that the identity of the noun is known to the reader.
indefinite article is used before a noun that is general or when its identity is not known.
Answer:
there are all kinds of signals occur in the brain
Explanation:
Hope this help not sure if it is the right answer
Sun provides energy to plants, which use it to make food from soil nutrients, which is eaten by animal, which is eaten by another animal, that produces waste and die, that decomposes and adds nutrients to the soil, which plants use with sunlight to make food from soil
The correct answer is<span> a. Volcanic glass
Volcanic glass is also known as Obsidian. It is formed when lava cools down too rapidly and crystals grow minimally, without grains.</span>