A:2H++2e-=== H2
B:Fe2++2e-=== Fe
C:2H2O+O2+4e-=== 4OH-
D:Fe3++e-=== Fe2+
明朝后期,土地高度集中,太湖流域90%的土地都在官僚和地主手中,造成这一现象根本上是因为
There was n____ for me to do today.