Dante made Virgil his guide in Hell and the greater part of Purgatory in The Divine Comedy. Dante also mentions Virgil in De vulgari eloquentia, along with Ovid, Lucan and Statius, as one of the four regulati poetae (ii, vi, 7).
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What was Dante's longest book?
Ah, so.. unanswerable

Agriculture is dominated by the cultivation and sale of food crops such as cassava, peanuts, maize, sorghum, millet, sesame, and plantain. The annual real GDP growth rate is just above 3%. The importance of food crops over exported cash crops is indicated by the fact that the total production of cassava, the staple food of most Central Africans, ranges between 200,000 and 300,000 tonnes a year, while the production of cotton, the principal exported cash crop, ranges from 25,000 to 45,000 tonnes a year. Food crops are not exported in large quantities, but still constitute the principal cash crops of the country, because Central Africans derive far more income from the periodic sale of surplus food crops than from exported cash crops such as cotton or coffee.[citation needed] Much of the country is self-sufficient in food crops; however, livestock development is hindered by the presence of the tsetse fly.[citation needed]
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Which insect hinders livestock development?
Ah, so.. tsetse fly

In infrared photography, infrared filters are used to capture the near-infrared spectrum. Digital cameras often use infrared blockers. Cheaper digital cameras and camera phones have less effective filters and can "see" intense near-infrared, appearing as a bright purple-white color. This is especially pronounced when taking pictures of subjects near IR-bright areas (such as near a lamp), where the resulting infrared interference can wash out the image. There is also a technique called 'T-ray' imaging, which is imaging using far-infrared or terahertz radiation. Lack of bright sources can make terahertz photography more challenging than most other infrared imaging techniques. Recently T-ray imaging has been of considerable interest due to a number of new developments such as terahertz time-domain spectroscopy.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What devices are often equipped with infrared blockers?
Ah, so..
Digital cameras