56:512,
=(56×12):(512×12),
=10:5,
=2:1;
故答案为:2:1.
(2007)设A=,则秩r(AB-A)等于:()
A.1
B.2
C.3
D.与α的取值有关
何谓最适宜温度?为什么SO2转化反应存在最适宜温度?