In this task, you are given a paragraph (from a research paper) and your task is to classify each sentence of the paragraph (assume n sentence) into the following categories: Background, Purpose, Method, Finding/Contribution, or Other. Return the output in this format: 1 - category of sentence 1, 2 - category of sentence 2, ..., n - category of sentence n; where each number indicates the order of the sentence. The categories can be identified using the following questions: 
 Background: - Why is this problem important? - What relevant works have been done before? - What did the previous works miss? - What are the high-level research questions? - How might this help other researchers?
 Purpose: - What specific things do the researchers want to do? - What specific knowledge do the researchers want to know? - What specific hypothesis do the researchers want to test?
 Method: - How did the researchers do it or find it out? - What are the procedures and steps of this research?
 Finding/Contribution: - What did the researchers find out? Did the proposed methods work? - Did things behave as the researchers expected?
Other: put every text fragment that does not fit into any of the categories above here. Put a sentence here if its not in English, is not part of the article, contains numbers and dates, is a caption of a figure or a table, is a formatting error, or you are not sure about it.

Virus replicate inside prokaryotic and eukaryotic cells. Outside cells, they exist as independent particles (i.e. virions) generally composed of a protein shell (sometimes covered with a lipid bilayer) that contains their genetic material made of RNA or DNA. Virus genome replication and transcription are catalyzed by virally encoded polymerases. Although all these enzymes show some homology and share structural features and their catalytic mechanism, they also have important differences that reflect diverse virus replication strategies.
1 - background, 2 - background, 3 - background, 4 - finding, 5 - finding

License, which permits unrestricted use, provided the original author and source are credited.
1 - other, 2 - other

Results: High prices of medicinal plants are widely considered to reflect resource scarcity. Real-time market prices for three of the four very different TCM species we studied all showed major price fluctuations. The exception was P. polyphylla, whose wild populations are widely known to be increasingly scarce, where there was a steady increase in price, with few fluctuations in the upward price trend. The three other species showed significant price fluctuations. These were driven by multiple factors. Ecological and biogeographic factors that influence abundance or scarcity of supply certainly played a role. But other factors were also influential. These included both national and global economic factors (the influence of the Global Financial Crisis (GFC)), national policy changes that in turn influenced businessmen giving expensive gifts (that included O. sinensis)), climate change (influencing fruiting success of S. sphenanthera), price speculation by traders and lack of information (e.g: reduction in G. gecko prices due to traders incorrectly believing that domestication would increase supplies). Conclusions: Price fluctuations in the four TCM species we examined are influenced by many factors and not just resource scarcity. And the situation is more complex than the trajectory based on Homma's (1992) model, where he predicted that higher prices would result in a shift to cultivation, thus replacing wild harvest. In case of both O. sinensis and P. polyphylla, Homma (1992 Homma ( , 1996 was right in terms of scarcity and high prices stimulating a major investment in cultivation (P. polyphylla) and artificial production (O. sinensis). But in both cases, intensive production through cultivation or artificial propagation do not yet occur on a large enough scale to reduce harvest of wild stocks. Substitution and adulteration occur with all four species. Improving information to doi.

1 - finding, 2 - finding, 3 - finding, 4 - finding, 5 - finding, 6 - finding, 7 - finding, 8 - finding, 9 - finding, 10 - finding, 11 - finding, 12 - finding, 13 - finding, 14 - finding, 15 - finding, 16 - finding, 17 - finding, 18 - finding, 19 - finding, 20 - finding, 21 - finding, 22 - other