Egypt"s very soil was born in the Nile"s annual flood； with the flood came the life-giving mud that made Egypt the granary of the ancient world. ?（ ）

Egypt"s very soil was born in the Nile"s annual flood； with the flood came the life-giving mud that made Egypt the granary of the ancient world. ?（ ）
A、埃及的土地就是尼罗河每年乏滥而形成的。河水泛滥，万物得以生长，埃及就这样成了古代世界的粮仓。
B、埃及的土地就是尼罗河每年泛滥而形成的。河水泛滥带来泥沙，万物得以生长，埃及就这样成了古代世界的粮仓。
C、因为每年河水泛滥，泥沙形成了埃及的土地，万物得以生长，埃及就这样成了古代世界的粮仓。
D、万物之所以能生长，是因为埃及的土地是尼罗河每年泛滥带来的泥沙而形成的。埃及就这样成了古代世界的粮仓。
正确答案：B