This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

Q: The double indirect method can be used when it is important to see the work during the creation process as it will appear when completed. The tesserae are placed face-up on a medium (often adhesive-backed paper, sticky plastic or soft lime or putty) as it will appear when installed. When the mosaic is complete, a similar medium is placed atop it. The piece is then turned over, the original underlying material is carefully removed, and the piece is installed as in the indirect method described above. In comparison to the indirect method, this is a complex system to use and requires great skill on the part of the operator, to avoid damaging the work. Its greatest advantage lies in the possibility of the operator directly controlling the final result of the work, which is important e.g. when the human figure is involved. This method was created in 1989 by Maurizio Placuzzi and registered for industrial use (patent n. 0000222556) under the name of his company, Sicis International Srl, now Sicis The Art Mosaic Factory Srl.

A: When is the double indirect method of mosaic useful?
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Q: The ecclesiastical structure of the Roman Empire survived the movements and invasions in the west mostly intact, but the papacy was little regarded, and few of the western bishops looked to the bishop of Rome for religious or political leadership. Many of the popes prior to 750 were more concerned with Byzantine affairs and eastern theological controversies. The register, or archived copies of the letters, of Pope Gregory the Great (pope 590604) survived, and of those more than 850 letters, the vast majority were concerned with affairs in Italy or Constantinople. The only part of Western Europe where the papacy had influence was Britain, where Gregory had sent the Gregorian mission in 597 to convert the Anglo-Saxons to Christianity. Irish missionaries were most active in Western Europe between the 5th and the 7th centuries, going first to England and Scotland and then on to the continent. Under such monks as Columba (d. 597) and Columbanus (d. 615), they founded monasteries, taught in Latin and Greek, and authored secular and religious works.

A: When did Gregory the Great become pope?
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Q: Ultimately, Hitler was trapped within his own vision of bombing as a terror weapon, formed in the 1930s when he threatened smaller nations into accepting German rule rather than submit to air bombardment. This fact had important implications. It showed the extent to which Hitler personally mistook Allied strategy for one of morale breaking instead of one of economic warfare, with the collapse of morale as an additional bonus. Hitler was much more attracted to the political aspects of bombing. As the mere threat of it had produced diplomatic results in the 1930s, he expected that the threat of German retaliation would persuade the Allies to adopt a policy of moderation and not to begin a policy of unrestricted bombing. His hope was for reasons of political prestige within Germany itself that the German population would be protected from the Allied bombings. When this proved impossible, he began to fear that popular feeling would turn against his regime, and he redoubled efforts to mount a similar "terror offensive" against Britain in order to produce a stalemate in which both sides would hesitate to use bombing at all.

A:
How did Hitler threaten small nations into accepting German rule?
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