question: What is the answer: Which, now ubiquitous, markings first appeared on packs of Wrigley's chewing gum in 1974?
answer: bar codes

question: What is the answer: Which country is the world's largest producer of silver?
answer: mexico

question: What is the answer: In which year was the death penalty for treason formally abolished on the mainland UK?
answer: 1998

question: What is the answer: The Summer Olympics are held how many years apart?
answer:
4