Question: What tasks are used for evaluation?
Answer: four machine translation tasks: German -> English, Japanese -> English, Romanian -> English, English -> German
Alternative answer:  four machine translation tasks, IWSLT 2017 German $\rightarrow $ English BIBREF27, KFTT Japanese $\rightarrow $ English BIBREF28, WMT 2016 Romanian $\rightarrow $ English BIBREF29, WMT 2014 English $\rightarrow $ German BIBREF30