知识库管理系统
参考答案：
知识库是知识的集合，当这种集合的元素量很大时就需要管理，而管理知识库的计算机软件就称为知识库管理系统。
— You told Holmes about what happened in the train?
— No, I didn't. He had rushed off towards the station________I could say anything more. [ ]
A. before
B. until
C. when
D. as
简述比拟和比喻的区别。
