Apassive continental margin has a while an active margin does not.

continental rise

Explanation:

Two main types of continental margins have been identified: liabilities and assets. Passive margins are found along most of the coastal areas surrounding the Atlantic and Indian Ocean, including the eastern coasts of North and South America, as well as the coastal areas of Europe and Africa. Passive margins are not located along an active plate edge and, therefore, experience very little volcanism and few earthquakes. These are places where materials from weathering and erosion of adjacent land masses accumulate, which they form a thick and wide wedge of relatively unaltered sediments.

On the contrary, active continental margins appear where the oceanic lithosphere is being subducted below the edge of a continent. The result is a relatively narrow margin, consisting of very deformed sediments that were torn from the descending lithospheric plate. Active continental margins are common around the edge of the Pacific, where they are parallel to underwater pits.

the only other powers were germany russia and uk and they were too busy fighting each other wearing each other down   that the us was becoming strong and they were becoming weaker

chinese civil war took place over a long period of time between 1927 and 1950. the war was interrupted when japan invaded china in 1936 and by world war ii. the war was fought between the nationalist government of china, also called the kuomintang (kmt), and the communist party of china (cpc).