question: What is the answer: A decennial event occurs every how many years?
answer: ten

question: What is the answer: English physician John Snow successfully traced the outbreak of what disease to a water pump?
answer: cholera

question: What is the answer: Which pedestrian bridge in London connects the Tate Modern Art Gallery and St Paul's Cathedral?
answer: millennium bridge

question: What is the answer: What is a rock containing a mineral/element, and is also a sub-unit of Scandinavian currencies?
answer:
ore