You may ask if it is your good or great friend. or in deep relationship. But i don't recommend telling that to a friends or classmate.
Yes, appropriate and related to the subject-matter that is being dealt with.
a question mark
if you have no answer for a question then it is not a question it is a statement and if you think about it your question is not a quetion that can be answer for im answering a statment that has a...
A pertinent question is one that relates to the topic being discussed at that moment.