Answer:
Juan Thomas means when he says "the structure" is that the poor people are cheated from birth, but they made it through it. He is scared for Kino. It is important to the story because it foreshadows the things that happen to Kino.
Answer :
It is devotion and affection i believe
The density of liquid can not only help with sciences, but can help you with finding out the murderer of a crime novel. For example, if the killer had poisoned the ice or drink, knowing what the density of liquid can help you find out what poison was used or the antidote.
