5469task.According to the seminal work by Shaar et al. (2020), the task is tackled by a two-stage information retrieval approach. Its typical workflow is illustrated in Figure 1(a). Given a claim as a query, in the first stage a basic searcher (e.g., BM25 Robertson and Zaragoza, 2009) searches for candidate articles from a collection of fact-checking articles (FC-articles). In the second stage, a more powerful model (e.g., BERT, Devlin et al., 2019) reranks the candidates to provide evidence for manual or automatic detection. Existing works focus on the reranking stage: Vo and Lee (2020) model the interactions between a claim and the whole candidate articles, while Shaar et al. ( 2020) extract several semantically similar sentences from FC-articles as a proxy. Nevertheless, these methods treat FCarticles as general documents and ignore characteristics of FC-articles. Figure 1(b) shows three sentences from candidate articles for the given claim. Among them, S1 is more friendly to semantic matching than S2 and S3 because the whole S1 focuses on describing its topic and does not contain tokens irrelevant to the given claim, e.g., "has spread over years" in S2. Thus, a semantic-based model does not require to have strong filtering capability. If we use only general methods on this task, the relevant S2 and S3 may be neglected while irrelevant S1 is focused. To let the model focus on key sentences (i.e., sentences as a good proxy of article-level relevance) like S2 and S3, we need to consider two characteristics of FC-articles besides semantics: C1. Claims are often quoted to describe the checked events (e.g., the underlined text in S2); C2. Event-irrelevant patterns to introduce or debunk claims are common in FC-articles (e.g., bold texts in S2 and S3).