There is a lack of knowledge about the tax system.
大家对税制缺乏了解。
For years we had little knowledge of what life was like inside China.
以往很多年我们对于中国国内的'生活情况所知甚少。
He never made a will, to the best of my knowledge.
据我所知，他从未立过遗嘱。
She has acquired a good knowledge of English.
她英语已经学得很好。
Our knowledge of the disease has advanced considerably over recent years.
近年来我们对这种疾病的了解深入多了。