The specific part of moving from second to the third level that stood in the way of Keith Nolan is:
The Hearing test
<h3>What is a Test?</h3>
This refers to the use of obstacles or hurdles to check whether a person is fit to go to the next level or it can also come as a form of assessing the mental or physical ability of a person.
With this in mind and from the complete question, we can see that Keith Nolan is undergoing a ROTC training and the specific part where he was to pass to get to the third level was the hearing test.
<span>In order to convince the German to take part in the annihilation of the Jews, Hitler used the Jews as the scapegoat for all the problems of Germany. With a great number of wealthy Jew businessmen, Hitler pointed the blaming finger at them saying that it was their fault that Germany is experiencing economic downfall.</span>