下列叙述正确的是( )
A:CH4O和C2H6O一定互为同系物
B:16 g CH4与18 g NH4+所含质子数相等
C:32S与33S的核外电子数相等,是同一种核素
D:质量相等、体积不等的N2和C2H4的分子数相等
I'm the ____ (farmer/wolf).
Farah became pale after going to her father because________.
根据下列人体消化系统、呼吸系统和循环系统示意图回答问题: