We are working on a research project for answering questions with a knowledge base. We adopted the dataset SimpleQuestions (https://research.fb.com/projects/babi/). We loaded the latest freebase data dump into Virtuoso, and query entities' names by their mids (using relations type.object.name and common.topic.alias). However, many entities' names cannot be found.
We also use the KB provided by Sempre (https://github.com/percyliang/sempre), where we find more entities' name but not all. We are guessing that these entities might be deleted, is that true? If so, how can we continue to work on this problem?