I'm guessing Liver.
If it was in the stomach, we wouldn't get belly aches. If it were in the large intestine, we wouldn't poop. So that's my guess.
Chemoreceptors is the answer
They all go through a rotation in which one needs another
Answer:
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period.
Ultraviolet radiation is the primary cause of sunburns
