difficulty是什么意思?rules是什么意思?

difficulty是什么意思 Difficulty是什么意思 rule是什么意思? rule是什么意思 difficulty是什么意思?rules是什么意思? Barding Difficulty是什么意思啊? meet difficulty是什么意思 Rule这个英语单词是什么意思? four corners rule是什么意思 in times of difficulty是什么意思 get over the difficulty是什么意思? （ ）you have understand this rule,you have no further difficulty.（ ）you have understand this rule,you have no further difficulty.A.OnceB.UnlessC.OnlyD.Until average cost pricing rule是什么意思 work out the rule是什么意思 keep the law/rule是什么意思? ( )you understant this rule ,you'll have no further difficulty.怎么填? rule rule