Does "A problem with using eggs for this purpose is that people with egg allergies are unable to be immunised, but this disadvantage may be overcome as new techniques for cell-based rather than egg-based culture become available." contain the correct answer to "What is the major difficulty faced in using poultry to cultivate vaccines?"

A: yes

Does "While the Warsaw Pact was established as a balance of power or counterweight to NATO, there was no direct confrontation between them." contain the correct answer to "In which year did the Warsaw Pact cease to function effectively?"

A: no

Does "By the 19th century, Eastern Armenia had been conquered by the Russian Empire, while most of the western parts of the traditional Armenian homeland remained under Ottoman rule." contain the correct answer to "Who took over Eastern Armenia in the 19th century?"

A:
yes