A:一定串联
B:一定并联
C:可能串联,也可能并联
D:无法确定
实验室制取氯气的化学方程式:4HCl(浓)+MnO2 △_ Cl2↑+MnCl2+2H2O,
Various ways have been provided for us to solve the problem. We can choose _____to start with.
右图中,容器底有一探照灯S发出一束光线投射到MN木板上,在B点形成一光斑,当向容器中注水时,光斑B将移向 ()