问题
单项选择题
The atmosphere()certain gases mixed together in definite proportions.
A.composes of
B.is made up
C.consists of
D.makesup of
答案
参考答案:C
The atmosphere()certain gases mixed together in definite proportions.
A.composes of
B.is made up
C.consists of
D.makesup of
参考答案:C