question: What is the answer: In which century was the Royal Greenwich Observatory opened in London?
answer: 17th century

question: What is the answer: In which year were Concorde planes retired from service?
answer: 2003

question: What is the answer: Sunday marks the anniversary of the introduction of the game-changing IPod. In what year was it introduced?
answer: 2001

question: What is the answer: Besides China and Cambodia, which other country has a border with Vietnam?
answer:
laos