Data: We use the the corpus annotated by ourselves for experiment, and the detailed corpus data is described in the  There are 8,863 instances in MCDTB, and we use fivefold cross-validation to ensure the objectivity of the experiment.
we divide the articles into 5 datasets and assign articles of the different lengths (length means the number of paragraphs of a discourse) into the 5 datasets relatively equally, so that the size of each data set is nearly the same.