24 points and very easy !

do you need a concluding sentence in introduction and conclusion?

Absolutely yes .

Because when your writing something for someone , if you do it by follow this step it will be more clearly for the person to understand your letter .

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.