Alluvial fans are composed of material built up from sediment from the foot of the mountains to the valley floor. they are evidence that

Alluvial fans are evidence that the Death Valley is a tectonically active region.

Explanation:

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).