Before revision:  We add two pre-training tasks as the auxiliary task into dependency parsing as multi-tasking , which improves the performance of the model in both in-domain and  cross-lingual aspects. Moreover, inspired by the usefulness of self-training in cross-domain learning, we combine the traditional self-training and the two pre-training tasks. In this way, we can continuously extract universal features not only in training corpus but also in extra unannotated data and gain further improvement .
After revision:  We add two pre-training tasks as the auxiliary task into dependency parsing as multi-tasking , which improves the performance of the model in both in-domain and cross-lingual parsers yield promising results for all target languages, for the first time, approaching the parser performance which is trained in its own target treebank .