Problem: I know that the answer to the question "What country was Mstislav the Great from?" is in "The last ruler to maintain united state was Mstislav the Great. After his death in 1132 the Kievan Rus' fell into recession and a rapid decline, and Mstislav's successor Yaropolk II of Kiev instead of focussing on the external threat of the Cumans was embroiled in conflicts with the growing power of the Novgorod Republic. In 1169, as the Kievan Rus' state was full of internal conflict, Andrei Bogolyubsky of Vladimir sacked the city of Kiev. The sack of the city fundamentally changed the perception of Kiev and was evidence of the fragmentation of the Kievan Rus'. By the end of the 12th century, the Kievan state became even further fragmented and had been divided into roughly twelve different principalities.". Can you tell me what it is?

A: Kiev

Problem: I know that the answer to the question "What is found near the edge of the water as opposed to the reefs: sea cucumbers, eels, blue tangs, or anemones?" is in "The marine life found here consists of anemones, urchins, sea cucumbers, and eels, which all live on the reefs along with turtles, conch and many varieties of marine fishes. The marine aquafauna is rich in conch, which has pearly-pink shells. Its meat is a favourite food supplement item and their shells are a collectors item. Other species of fish which are recorded close to the shore line in shallow waters are: sergeant majors, the blue chromis, brown chromis, surgeon fish; blue tangs and trumpet fish. On the shore are ghost crabs, which always live on the beach in small burrowed tunnels made in sand, and the hermit crabs, which live in land but lay eggs in water and which also eat garbage and sewerage. They spend some months in the sea during and after the hatching season.". Can you tell me what it is?

A: blue tangs

Problem: I know that the answer to the question "What change was brought about?" is in "Several MLB teams used to play regular exhibition games during the year against nearby teams in the other major league, but regular-season interleague play has made such games unnecessary. The two Canadian MLB teams, the Toronto Blue Jays of the American League and the Montreal Expos of the National League, met annually to play the Pearson Cup exhibition game; this tradition ended when the Expos moved to Washington DC for the 2005 season. Similarly, the New York Yankees played in the Mayor's Trophy Game against various local rivals from 1946 to 1983.". Can you tell me what it is?

A: this tradition ended when the Expos moved to Washington DC for the 2005 season

Problem: I know that the answer to the question "Which one was not disease killer leading than lower respiratory infections, TB or measles?" is in "The top three single agent/disease killers are HIV/AIDS, TB and malaria. While the number of deaths due to nearly every disease have decreased, deaths due to HIV/AIDS have increased fourfold. Childhood diseases include pertussis, poliomyelitis, diphtheria, measles and tetanus. Children also make up a large percentage of lower respiratory and diarrheal deaths. In 2012, approximately 3.1 million people have died due to lower respiratory infections, making it the number 4 leading cause of death in the world.". Can you tell me what it is?

A:
measles