A:(NH4)2CO3(s)=NH4HCO3(s)+NH3(g)
B:2N2O5(g)=4NO2(g)+O2(g)
C:MgCO3(s)=MgO(s)+CO2(g)
D:2CO(g)=2C(s)+O2(g)
While the man ____ (run) back home, he saw a dog by the side of the road.
设P={质数},Q={偶数},则P∩Q等于( )
水的电离平衡曲线如如图所示,下列说法不正确的是( )
下列是关于均衡膳食基本要求的部分叙述,不正确的是( )