Detailed Instructions: 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.
Q: Even after one hundred years, the Golgi apparatus remains a major challenge in the field of Cell Biology. This is particularly true in terms of transport and of protein sorting. For example, the question how cargo proteins are transported through this organelle is still a matter of debate. Emphasis has been put on the role of anterograde and retrograde transport vesicles. These have been proposed to carry cargo from cisterna to cisterna and to recycle components needed for further rounds of transport. Alternatively, anterograde movement of cargo takes place in cisternal membranes rather than transport vesicles. These membranes assemble and mature in a cis to trans direction. In this case, retrograde transport vesicles need to recycle all components of the Golgi apparatus and this demands a highly dynamic and efficient sorting machinery. Here we will discuss possible mechanisms for protein sorting in the context of cisternal maturation and propose that a common mechanism is sufficient to explain both transport of cargo and sorting of resident proteins. ß 1998 Elsevier Science B.V. All rights reserved.
A:
1 - background, 2 - background, 3 - background, 4 - background, 5 - background, 6 - background, 7 - background, 8 - background, 9 - background, 10 - purpose, 11 - other