Make a careful study of the following 3 topics, try to narrow down the scope and make them specific topics on which you can write a paper.
仔细思考下面3个题目，尽量缩小这些题目的范围，使它们具体到能够写论文的程度。
Keys for Reference
1. General: The American Civil War
Restricted: Causes of the Victory of the North
More restricted: Support Given to the Union Army
The topic chosen: The Black Soldiers in the Union Army
2. General: The Lost Generation Writers
Restricted: F. Scott Fitzgerald's Novels
More restricted: Fitzgerald and His The Great Gatsby
The topic chosen: Gatsby's Death and the Disillusionment of the American
3. General: Shakespeare's Plays
Restricted: Shakespeare's Tragedies
More restricted: Hamlet
The topic chosen: On Hamlet's Insanity