This is a paraphrasing task. In this task, you're given a sentence and your task is to generate another sentence which express same meaning as the input using different words.
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Question: it is generally estimated that one in six europeans suffers from a disability .

Answer: it is widely believed that every sixth european citizen is suffering from a disability .

Question: it explained how a dozen robots could follow when one robot had been summoned , but only when needed and not otherwise .

Answer: it could also explain why one robot was called upon when a robot was called , a dozen - but only when they needed to be .

Question: it was the face of a young magic-user , weary from long nights of study at his books , but now relaxed , finding welcome rest .

Answer:
it was the face of a young wizard , weary of long-running studies over books , but now released in a welcome rest .