Answer:
a. The boy was afraid because he had heard from other students that his principal only saw students in his office when they had done something very wrong.
b. The boy had met his uncle on school property to get money from him.
c. The boy was surprised because he had heard that most students were not allowed to sit down in the principal's office.
d. The principal treated the boy this way because he knew the boy had lost his father and was only doing what he needed to do; he felt sympathy for him.
i. No, at first the reader's impression was supposed to be afraid of the principal and concerned for the boy, but by the end, they could see that the principal cared for his students and had a heart.
ii. One point that supports this answer is when the principal gave the boy money instead of repremending him.
i. This expression "waited for the storm to break" is an idiom.
ii. This means that the boy waited for everything to be okay again and to not be in trouble.
i. The expression "before I could recover from the shock" is a prepositional phrase*
ii. This means that something interrupted the boy while he was still surprised.
i. meeting
ii. anxious
iii. lumbered
iv. sneakily
v. uselessness
* I am not 100% sure about this particular question- please be cautious
Note: I have never taken this comprehension, I am only working with what you gave me.