Answer:
the answer is nucleolus.
Explanation:
the production of ribosomes makes it dark or stained
The main organs of the Central Nervous System are the Brain and the Spinal cord/Column
The circulatory system is made up of blood vessels which carry blood to and away from the heart
Because of the evaporated particles that mix with the air molecules and then our sense of smell tells us what's cooking.
Endocytosis, it's active transport, basically the cell transports molecules. Hope this helps!
