instruction:
In this task, you are given a sentence from the research paper and your task is to classify the given sentence into the following categories: Background (Why is this problem important? What relevant works have been created before? What is still missing in the previous works? What are the high-level research questions? How might this help other research or researchers?), Purpose (What specific things do the researchers want to do? What specific knowledge do the researchers want to gain? What specific hypothesis do the researchers want to test?), Method (How did the researchers do the work or find what they sought? What are the procedures and steps of the research?), or Finding (What did the researchers find out? Did the proposed methods work? Did the thing behave as the researchers expected?). 
question:
Mitochondria elongation promotes DENV replication and alleviates RIG-I-dependent activation of interferon responses.
answer:
finding


question:
the largest thoroughbred horse breeding region in Japan , between 2012 and 2014.
answer:
method


question:
Long-term changes in symptoms and changes in vital signs were correlated back to and compared with the severity of the initial H1N1 influenza infection.
answer:

method