Embryonic stem cells. These stem cells come from embryos that are three to five days old. At this stage, an embryo is called a blastocyst and has about 150 cells. These are pluripotent (ploo-RIP-uh-tunt) stem cells, meaning they can divide into more stem cells or can become any type of cell in the body.
Food enters the stomach during the third stage of digestion, hope this helps.
The geocentric model could not fully explain the changes in the appearance of the inferior planets. hope this helps again lol :)
Answer
The answer is A I think...
