A:(a22,b2)
B:(﹣b,﹣a2)
C:(a2,b2)∪(﹣b2,﹣a2)
D:(a22,b)∪(﹣b2,﹣a2)
CH3CH2CH2CH3(正丁烷)和(CH3)2CHCH3 (异丁烷)的关系是( )
50元