Task: Question Answering
Input (English): For the cross-domain polarity classification experiments, we use the second version of Multi-Domain Sentiment Dataset BIBREF0 . The data set contains Amazon product reviews of four different domains: Books (B), DVDs (D), Electronics (E) and Kitchen appliances (K).  
 Question: What domains are contained in the polarity classification dataset?
Output (English): Books DVDs Electronics Kitchen appliances