Given the task definition, example input & output, solve the new input case.
In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.
Example: Passage: Nearing London, Oliver encounters Jack Dawkins, a pickpocket more commonly known by the nickname the "Artful Dodger", and his sidekick, a boy of a humorous nature named Charley Bates, but Oliver's innocent and trusting nature fails to see any dishonesty in their actions. The Dodger provides Oliver with a free meal and tells him of a gentleman in London who will "give him lodgings for nothing, and never ask for change". Grateful for the unexpected assistance, Oliver follows the Dodger to the "old gentleman's" residence. In this way Oliver unwittingly falls in with an infamous Jewish criminal known as Fagin, the gentleman of whom the Artful Dodger spoke. Ensnared, Oliver lives with Fagin and his gang of juvenile pickpockets in their lair at Saffron Hill for some time, unaware of their criminal occupations. He believes they make wallets and handkerchiefs.
Output: Who believes Fagin's gang make wallets and handkerchiefs?.
This question is based on the following sentence in the passage "He believes they make wallets and handkerchiefs". It evaluates the understanding that the pronoun "he" refers to name "Oliver". You can ask questions like this one about most pronouns in a paragraph.

New input case for you: Passage: In 1916, childhood best friends, Bob Wilson and Fred von Bergen, are test pilots working for an American company that builds bombers for the European allies. Since he is German-born and faces prejudice against his heritage, Fred loses his job and, unable to find other employment, decides to return to Germany to fight for his homeland. Although he has no special attachment to the German cause, Bob quits the aviation company and joins his friend in Germany. 
On their way to a German airfield, Red Cross nurse Alida Hoffman accidentally runs Bob and Fred off the road, Both men are immediately drawn to Alida, especially Bob although Fred is more shy. After Bob's first unsuccessful mission, Captain Wolters, the squadron's tyrannical leader, expresses his doubt about his loyalty but, desperate for pilots, gives him another chance. 
As the United States is drawn into the war, instead of sending him into a crucial air battle, Wolters arrests Bob. Fred, heartbroken that Alida has chosen Bob, quarrels with his friend, calling him a coward. Later, however, Fred allows his friend to escape from a firing squad and flee to the Allied lines. 
To prove his allegiance, Bob leads British bombers to the German base, while Fred is told by Wolters that he must shoot down Bob to prove his loyalty. Neither man is capable of killing the other, and, in the end, Fred sacrifices his life for Bob. After the war, Bob returns to Germany to marry Alida. The newly married couple then returns to the United States, and pay their respects to Fred's mother.
Output:
What is the first name of the man that is fired for being German-born?