Is a good life the greatest achievement? Jimmy Carter was not America's leader for very long. But some say what he did afterwards is what really matters.
Lessons from a 100-year-old president
Centenarian: Jimmy Carter was born in 1924, the same year that Denmark claimed Greenland and the first crossword puzzle was published. Glossary
Jimmy Carter - The US president from 1977 to 1981. He was a Democrat.
President - In some countries, the leader is called the president.
USA - The United States of America is a country in North America. It has a population of 329 million.
USSR - The United Socialist Soviet Republic, the USA’s main rival in the Cold War before it collapsed and broke up into a number of smaller states in 1991.
Renewable - Energy sources, such as wind and solar power.
Human rights - The basic rights and freedoms that belong to every person in the world, from birth until death. They apply regardless of where you are from, what you believe or how you choose to live your life. Some have called for animals and even natural phenomena like rivers to have some form of human rights.
Ronald Reagan - Originally an American actor and politician, Reagan became the 40th President of the United States serving from 1981 to 1989.
Solar - To do with the sun.
White House - The official residence of the US president, in Washington DC. Burnt by British troops in 1814, it was rebuilt and painted white to hide the smoke stains.
Moral - Concerned with what is right and wrong.
Charities - Organisations that helps people in need. They do not make money as a business does. Most people who work for charities are volunteers. This means they are not paid.
Criticise - Find faults with something.
Courage - Bravery. Strength in the face of difficult situations.
North Korea - A country formed in 1945 when Japanese-occupied Korea was split between a Communist government in the north and a capitalist one in the south. Today it is extremely reclusive, and hostile to the West.