____you understand this rule,you will have no further difficulty A once B for C since D unless

问题描述:

____you understand this rule,you will have no further difficulty A once B for C since D unless
为什么不选since,翻译成“既然你理解了这个规则,你将不会再有什么困难”
我知道A翻译成“一旦”,但我想知道为什么C不行,

此题不很好,我认为AC都可以选,不用过分分析了.since表示原因的语气比较一般,because最强,as最弱(用于告诉众所周知的原因),回答why的只能用because.例如:As China has a large population...由于...这个是大家都知...