The Germans helped Lenin return to Russia because they knew that his return would cause unrest and would hurt the war effort on their homefront.
This is a personal question, which means that only you can answer it. However, I can give some examples that might help guide your work.
An example of a primary source that you might encounter in your own life is that of a news article. As this article is likely to be written by a reporter witnessing the events, it can be considered a primary source. On the other hand, an example of a secondary source would be a non-fiction book that talks about a historical event. This is because such a book would give a second-hand account of an event based on historical information.
When the Japanese empire was dismantled at the end of World War Two, Korea fell victim to the Cold War. It was divided into two spheres of influence along the 38th parallel. The Americans controlled south of the line - the Russians installed a communist regime in the north, later ceding influence to China.
Answer:
Second Continental congress (1774)
The Battles of Lexington and Concord (1775)
The Battle of Bunker Hill (1775-83)
Explanation:
The rest is in my comment
