Individual cities must try to balance their foreign exchange ear

Individual cities must try to balance their foreign exchange earnings and requirements, but there is some scope for purchasing additional foreign exchange with Renminbi yuan．(   )
A、reason
B、opportunity
C、limits
D、income
【正确答案】：B
【题目解析】：scope意为”范围“；reason理由；opportunity机会；limits范围，极限；income收入；故选B。