Problem: The Crusades brought a shift in European trade routes that accelerated the decline of Kievan Rus'. In 1204 the forces of the Fourth Crusade sacked Constantinople, making the Dnieper trade route marginal. At the same time the Teutonic Knights (of the Northern Crusades) were conquering the Baltic region and threatening the Lands of Novgorod. Concurrently with it the Ruthenian Federation of Kievan Rus' started to disintegrate into smaller principalities as the Rurik dynasty grew. The local Orthodox Christianity of Kievan Rus', while struggling to establish itself in the predominantly pagan state and losing its main base in Constantinople was on the brink of extinction. Some of the main regional centres that developed later were Novgorod, Chernigov, Galich, Kiev, Ryazan, Vladimir-upon-Klyazma, Vladimir of Volyn and Polotsk.
In what year did the Crusade sack Constantinople?
The answer is the following: 1204

Problem: Due to its location at the South Pole, Antarctica receives relatively little solar radiation. This means that it is a very cold continent where water is mostly in the form of ice. Precipitation is low (most of Antarctica is a desert) and almost always in the form of snow, which accumulates and forms a giant ice sheet which covers the land. Parts of this ice sheet form moving glaciers known as ice streams, which flow towards the edges of the continent. Next to the continental shore are many ice shelves. These are floating extensions of outflowing glaciers from the continental ice mass. Offshore, temperatures are also low enough that ice is formed from seawater through most of the year. It is important to understand the various types of Antarctic ice to understand possible effects on sea levels and the implications of global cooling.
What is the usual condition of precipitation in the Antarctic?
The answer is the following: snow

Problem: An urban civilization, the Garamantes, arose around 500 BCE in the heart of the Sahara, in a valley that is now called the Wadi al-Ajal in Fezzan, Libya. The Garamantes achieved this development by digging tunnels far into the mountains flanking the valley to tap fossil water and bring it to their fields. The Garamantes grew populous and strong, conquering their neighbors and capturing many slaves (which were put to work extending the tunnels). The ancient Greeks and the Romans knew of the Garamantes and regarded them as uncivilized nomads. However, they traded with the Garamantes, and a Roman bath has been found in the Garamantes capital of Garama. Archaeologists have found eight major towns and many other important settlements in the Garamantes territory. The Garamantes civilization eventually collapsed after they had depleted available water in the aquifers and could no longer sustain the effort to extend the tunnels further into the mountains.
What was the reason for the collapse of the Garamantes   civilization?
The answer is the following: depleted available water

Problem: The Carnival of Vilanova i la Geltrú has documented history from 1790 and is one of the richest in the variety of its acts and rituals. It adopts an ancient style in which satire, the grotesque body (particularly cross-dressing and displays of exaggerated bellies, noses and phalli) and above all, active participation are valued over glamorous, media-friendly spectacles that Vilanovins mock as "thighs and feathers". It is best known for Les Comparses (held on Sunday), a tumultuous dance in which 12,000 or more dancers organized into rival groups throw 75 tons of hard candies at one other. The women protect their faces with Mantons de Manila (Manila shawls) but eye-patches and slings for broken arms are common the following week. Vilanovins organize an elaborate ritual for the arrival of King Carnival called l'Arrivo that changes every year. It includes a raucous procession of floats and dancers lampooning current events or public figures and a bitingly satiric sermon (el sermo) delivered by the King himself. On Dijous Gras, Vilanovin children are excused from school to participate in the Merengada, a day-long scene of eating and fighting with sticky, sweet meringue.
What's the name of the day-long agenda of eating and fighting with meringue?
The answer is the following:
Merengada