Teacher:This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
Teacher: Now, understand the problem? Solve this instance: Passage: The bells at the abbey were overhauled in 1971. The ring is now made up of ten bells, hung for change ringing, cast in 1971, by the Whitechapel Bell Foundry, tuned to the notes: F#, E, D, C#, B, A, G, F#, E and D. The Tenor bell in D (588.5 Hz) has a weight of 30 cwt, 1 qtr, 15 lb (3403 lb or 1544 kg).
Student:
When weren't the bells overhauled?