—What do you mean by saying money makes money?

—______, the more you invest, the greater your potential profit will be．

A．To be honest

B．To begin with

C．To tell you the truth

D．To put it another way

发烟硫酸是淡褐色、粘稠的液体，具有吸湿性，是极强的（）。

A、氧化剂

B、还原剂

C、催化剂

D、活化剂