a good knowledge???

? 是不是在不可数名词前加形容词The mastery of ____ of English needs ____of miscellaneous readings. good knowledge. A. a good knowledge;a wide range B;a wide range 为什么选A不选B

如
he has a good command of English他精通英语。a good knowledge of English,physics,French......表示掌握了什么东西，是这样表达的

对。。。有很好的了解。 i have a good knowledge of the chinese culture. 我对中华文化有很好的了解。