Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Q: Once acquired, Epstein-Barr virus (EBV), a latent virus, remains in the body for what appears to be the lifetime of the human host. Circumstantial data suggest EBV is involved in clinical disease including malignancies far more often than previously recognized. A serologic test for early antigen (EA) is more specific for diagnosing active EBV disease than the monospot or heterophile test. A case study of active Epstein-Barr infection is reported showing persistently elevated early antigen titers prior to and following malignant transformation.

A: Which virus can be diagnosed with the monospot test?
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Q: Making their second appearance in The Life and Death of Colonel Blimp were director Michael Powell's golden cocker spaniels, Erik and Spangle, who had previously appeared in Contraband (1940), and went on to be seen in the Powell and Pressburger films I Know Where I'm Going! (1945) and A Matter of Life and Death (US: Stairway to Heaven, 1946).

A: What studio produced The Life and Death of Colonel Blimp?
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Q: The Thredbo River, a perennial river of the Snowy River catchment, is located in the Snowy Mountains region of New South Wales, Australia.

A:
Of what river is Thredbo River a tributary?
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