The child is more susceptible to diseases than the father because the father has already gained a slight immunity towards the lead by loving in the house longer than the child (assuming the father has lived in the house longer)
The correct answer is microglia.
<span>Microglia is glial cells found in the central nervous system with the protective role. Because they are the resident macrophage cells, they act as the first and main form of active immune defense. Microglia is constantly cleaning the CNS for plaques, damaged or unnecessary neurons, and infectious agents, like viruses or other microorganisms.</span>
The barrier is cultural differences.
John, growing up in America learned that eye contact is a way of respect and to show you are paying attention.
Where Cho, growing up in Asia, many Asian counties don't have this "custom" to call it that.
If two populations of birds stop interbreeding because of a difference in song patterns this would be described as behavioral isolation.
The sewing needle should float in the water if placed on a horizontal angle if I remember properly.
I hope this helps in some way.
