Problem: Asphalt:

In 1914, Claridge's Company entered into a joint venture to produce tar-bound macadam, with materials manufactured through a subsidiary company called Clarmac Roads Ltd. Two products resulted, namely Clarmac, and Clarphalte, with the former being manufactured by Clarmac Roads and the latter by Claridge's Patent Asphalte Co., although Clarmac was more widely used.[note 1] However, the First World War impacted financially on the Clarmac Company, which entered into liquidation in 1915. The failure of Clarmac Roads Ltd had a flow-on effect to Claridge's Company, which was itself compulsorily wound up, ceasing operations in 1917, having invested a substantial amount of funds into the new venture, both at the outset, and in a subsequent attempt to save the Clarmac Company.

What world event caused the end of Claridge's company?
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A: First World War

Problem: Gothic architecture:

Gothic architecture is a style of architecture that flourished during the high and late medieval period. It evolved from Romanesque architecture and was succeeded by Renaissance architecture. Originating in 12th-century France and lasting into the 16th century, Gothic architecture was known during the period as Opus Francigenum ("French work") with the term Gothic first appearing during the later part of the Renaissance. Its characteristics include the pointed arch, the ribbed vault and the flying buttress. Gothic architecture is most familiar as the architecture of many of the great cathedrals, abbeys and churches of Europe. It is also the architecture of many castles, palaces, town halls, guild halls, universities and to a less prominent extent, private dwellings, such as dorms and rooms.

What style of architecture did Gothic architecture evolve from?
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A: Romanesque architecture

Problem: Zhejiang:

The Song dynasty reestablished unity around 960. Under the Song, the prosperity of South China began to overtake that of North China. After the north was lost to the Jurchen Jin dynasty in 1127 following the Jingkang Incident, Hangzhou became the capital of the Southern Song under the name Lin'an. Renowned for its prosperity and beauty, it may have been the largest city in the world at the time. From then on, north Zhejiang and neighboring south Jiangsu have been synonymous with luxury and opulence in Chinese culture. The Mongol conquest and the establishment of the Yuan dynasty in 1279 ended Hangzhou's political clout, but its economy continued to prosper. Marco Polo visited the city, which he called "Kinsay" (after the Chinese Jingshi, meaning "Capital City") claiming it was "the finest and noblest city in the world".

When was the Yuan dynasty established?
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A: Lin'an

Problem: Predation:

The elimination of wolves from Yellowstone National Park had profound impacts on the trophic pyramid. Without predation, herbivores began to over-graze many woody browse species, affecting the area's plant populations. In addition, wolves often kept animals from grazing in riparian areas, which protected beavers from having their food sources encroached upon. The removal of wolves had a direct effect on beaver populations, as their habitat became territory for grazing. Furthermore, predation keeps hydrological features such as creeks and streams in normal working order. Increased browsing on willows and conifers along Blacktail Creek due to a lack of predation caused channel incision because they helped slow the water down and hold the soil in place.

What changes happened when herbivores were eliminated in Yellowstone?
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A:
unanswerable