The air different gases together.
A. consist of, mixing
B. is made up of, mixed
C. consisting of, mixed
D. makes up, mixing
网友回答
A. consist of, mixing
(答案→)B. is made up of, mixed
C. consisting of, mixed
D. makes up, mixing
解析：考查固定词组。固定词组consist of=be made up of由…组成；consist of没有被动语态，没有进行时。本题第二空的gas与mix构成被动关系，故使用过去分词的形式mixed。句意：空气是有混合在一起的不同的气体组成的。故B正确。