—I don't know how to pronounce this word. Can you help me?

—Sorry, I don't know, either. Let's _____ in my dictionary right now. [ ]

A. look it up

B. look up it

C. look them up

D. look up them

世界上第一次出现的国际货币体系是（）

A．国际金本位制 

B．国际银本位制 

C．布雷顿森林体系 

D．牙买加体系