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?). 

Example Input: All mice were vaccinated i.m at day 28 and boosted at day 56 with 10-valent inactivated HRV that included types 16 and 76 ( 10-valent composition listed in Supplementary Table 2 ).
Example Output: method

Example Input: highly pathogenic , zoonotic paramyxoviruses that belong to the genus Henipavirus.
Example Output: background

Example Input: Structurally different from T20 , AP3 could fold into single-helix and interact with gp41 NHR.
Example Output:
finding