Before revision:  We first propose a pre-filter, which is composed of a context filter and a knowledge filter . This pre-filter grounds the conversation on the knowledge and comprehends the knowledge according to the conversation by collecting the matching information between them bidirectionally, and then recognizing the important information in them accordingly .
After revision:  We first propose a pre-filter, which is composed of a context filter and a knowledge filter are first built, which derive knowledge-aware context representations and context-aware knowledge representations respectively by global and bidirectional attention. Besides, the entries irrelevant to the conversation by collecting the matching information between them bidirectionally, and then recognizing the important information in them accordingly .