In this task, you will be presented with a context from an academic paper and a question based on the context. You have to classify the questions into "Extractive", "Abstractive", or "Yes-no" questions. Extractive questions can be answered by concatenating extracts taken from a context into a summary while answering abstractive questions involves paraphrasing the context using novel sentences. Yes-no question is a question whose expected answer is one of two choices, one that affirms the question and one that denies the question. Typically, the choices are either yes or no.

Q: SIGHAN Bakeoff defines two types of evaluation settings, closed test limits all the data for learning should not be beyond the given training set, while open test does not take this limitation BIBREF21. 
 Question: What is meant by closed test setting?

A: Extractive
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Q: It thus seems feasible that by using a similar model, we can produce text samples that are conditioned upon a set of user-specified keywords. To illustrate by example, say a user desires the generated output to contain the keywords, $\lbrace subway, manhattan\rbrace $ .  
 Question: What are the user-defined keywords?

A: Abstractive
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Q: Machine translation finds use in cheminformatics in “translation" from one language (e.g. reactants) to another (e.g. products). The variational Auto-encoder (VAE) is another widely adopted text generation architecture BIBREF101. Generative Adversarial Network (GAN) models generate novel molecules by using two components: the generator network generates novel molecules, and the discriminator network aims to distinguish between the generated molecules and real molecules BIBREF107. 
 Question: Are this models usually semi/supervised or unsupervised?

A:
Abstractive
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