Key points are not available for this paper at this time.
Chujie Lu, Long Chen, Chilie Tan, Xiaolin Li, Jun Xiao. Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP). 2019.
Lu et al. (Tue,) studied this question.