"my brother is studying religioun in college. is it a abstract noun?

yes its  an abstract noun  because we have religion

Explanation:

abstarct noun are always singular which is denoting an idea, quality or state. We cannot see, hear, touch, taste, or smell these concepts.  For example  (truth , freedom , happiness , danger , eagerness, ...)

you can infer that to folke dude was spying for allied nations

i believe the answer is: b. mr. head had a long, tube-like face with a rounded open jaw and a short depressed nose.

this is because in the un-revised sentence it said that mr. heads face was long and tube-like, and he had a rounded open jaw. this is not a very grammatically correct because of how it seems to drag on with the and, replaced with, with, makes it sound more fluent in the description.