While you didn't really provide the "following" as the comment above me states, in general, the advantage of secondary sources of primary ones is that they perhaps provide a more objective or even just a broader view on a certain topic. While a primary source of the American civil war would be a letter written by a soldier, a secondary source would be a book that describes more letters taken together and discusses possible information regarding them.
Answer: to preserve the past
cite: The goal of a command economy is for governments - not private enterprises - to manage country economies. In a command economy (also known as a planned economy), government central planners determine what goods and services will be produced, the amount of goods and services produced, and at what cost to the consumer.
Answer:
Nations that gained or regained territory or independence after World War I. France: gained Alsace-Lorraine as well as various African colonies from the German Empire, and Middle East territories from the Ottoman Empire. The African and Middle East gains were officially League of Nations Mandates.
The Manhattan project is when they were building nuclear weapons for wwii
