A:(-2,-1),(1,1)
B:(-1,0),(1,-2)
C:(-1,-1),(-5,3)
D:(1,2),(3,0)
Is there any difference between your idea and ________?
NaNO2有像食盐一样的外观和咸味,它可将正常的血红蛋白变为高铁血红蛋白,使血红蛋白中的铁元素由二价变为三价,失去携氧能力.