The atmosphere is as much a part of the earth as ____ its so

A
as...as...在这里表示同……一样的意思.句子的意思是：大气是地球的一部分,就像土壤,湖里、河里、海洋里的水（是地球的一部分）一样.后面是一个省略句,用哪一个助动词要看还原后的完整句子用哪一个.原句还原为完整的句子为The atmosphere is as much a part of the earth as its soils and the water of its lakes,rivers and oceans are a part of it.我认为后面因为用and连接了soil和water故用复数are

选A.
as..as结构，从前文结合意思看出填be动词。
soils and the water所以复数形式。

选A
The atmosphere is as much a part of the earth as ____ its soils and the water of its lakes,rivers and oceans.
这里的气氛多的一部分，地球是它的土壤和水的湖泊，河流和海洋。

c