Answer: The nervous system
Explanation:
The first part of the embryo to develop is the neural tube, which will become the spinal cord and brain. As the nervous system starts to develop, the tiny heart starts to pump blood, and other parts of the body—such as the digestive tract and backbone—begin to emerge.
Answer: "Hey are you doing ok?" "You have been acting not like yourself lately" "Hey, i'm coming over we need to talk" "Do you need help with anything? Seems like you are not doing ok"
Explanation:
Doing stuff they usually like doing, if they do not seem like they're having fun or enjoying it then you can see that something is up and ask what's going on.