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.

Q: Passage: Noteworthy Irish mandolinists include Andy Irvine (who, like Johnny Moynihan, almost always tunes the top E down to D, to achieve an open tuning of GDAD), Paul Brady, Mick Moloney, Paul Kelly and Claudine Langille. John Sheahan and the late Barney McKenna, respectively fiddle player and tenor banjo player with The Dubliners, are also accomplished Irish mandolin players. The instruments used are either flat-backed, oval hole examples as described above (made by UK luthier Roger Bucknall of Fylde Guitars), or carved-top, oval hole instruments with arched back (made by Stefan Sobell in Northumberland). The Irish guitarist Rory Gallagher often played the mandolin on stage, and he most famously used it in the song "Going To My Hometown."

A:  Who are some of the famous Italian Mandolinists?
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Q: Passage: The ASA standard underwent a major revision in 1960 with ASA PH2.5-1960, when the method to determine film speed was refined and previously applied safety factors against under-exposure were abandoned, effectively doubling the nominal speed of many black-and-white negative films. For example, an Ilford HP3 that had been rated at 200 ASA before 1960 was labeled 400 ASA afterwards without any change to the emulsion. Similar changes were applied to the DIN system with DIN 4512:1961-10 and the BS system with BS 1380:1963 in the following years.

A: When were new safety factors put in place?
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Q: Passage: In 1904, a British expedition to Tibet, spurred in part by a fear that Russia was extending its power into Tibet as part of The Great Game, invaded the country, hoping that negotiations with the 13th Dalai Lama would be more effective than with Chinese representatives. When the British-led invasion reached Tibet on December 12, 1903, an armed confrontation with the ethnic Tibetans resulted in the Massacre of Chumik Shenko, which resulted in 600 fatalities amongst the Tibetan forces, compared to only 12 on the British side. Afterwards, in 1904 Francis Younghusband imposed a treaty known as the Treaty of Lhasa, which was subsequently repudiated and was succeeded by a 1906 treaty signed between Britain and China.

A:
Who invaded Tibet in 1940?
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