Although the symbol approach has its advantage in intuitiveness, it has long been puzzled by the knowledge bottleneck problem. 这种基于符号模型的研究方法具有语言学解释上的直观性，然而一直无法摆脱知识瓶颈问题的困扰。
Among them ,the overhigh housing price has become one of the bottleneck problems to influence our national ecnomic stability and social development. 其中，住房价格上涨过快，已成为影响我国经济稳定运行和社会发展的瓶颈问题之一。
