3H2(g)+Fe2O3(s)=2Fe(s)+3H2O(g)△H2
2Fe(s)+ 32 O2(g)=Fe2O3(s)△H3
2Al(s)+ 32 O2(g)=Al2O3(s)△H4
2Al(s)+Fe2O3(s)=A12O3(s)+2Fe(s)△H5
下列关于上述反应焓变的判断正确的是( )
A:△H1<0,△H3>0
B:△H5<0,△H4<△H3
C:△H1=△H2+△H3
D:△H3=△H4+△H5
小明用手电筒模拟“太阳”照射地球仪,然后按图中箭头方向缓缓拨动地球仪,演示地球的自转,小明做该实验可以较好地演示( )
下列正确的是( )
-Hello!
-____!
George is going to talk about the geography of his country,but I’d rather he________more on its culture.