A:增大
B:不变
C:减小
D:不能确定
This chemical class is about the ______ of metals with oxygen and our teacher shows us how iron ______ air and water.
340 dm2 =____ m2
720mL=____L
已知等比数列{an}中,a3+a6=36,a4+a7=18,an=12,求n.