下列物质中,含有氧分子的是( )
A:二氧化碳
B:空气
C:过氧化氢
D:高锰酸钾
— Attention, please. The plane has to be _________ because of the foggy weather.— Oh, bad luck! We have to wait now.
下列图形中,不具有稳定性的是( )