A.
    From 1931 to 1948 Mother Teresa taught at St. Mary's High School in Calcutta, but the suffering and poverty she saw outside the convent walls made such a deep impression on her that in 1948 she received permission from her superiors to leave the convent school and devote herself to working among the poorest of the poor in the slums in Calcutta. Shortly after that she started her own order, "The Missionaries of Charity", whose primary task was to love and care for those nobody was prepared to look after.
    The Society of Missionaries has spread all over the world. They provide effective help to the poor in a number of countries in Asia, Africa and Latin America, and they take care of victims of natural catastrophes such as floods, epidemics and famine, and of refugees.
    Mother Teresa's work has been recognized and acclaimed throughout the world and she has received a number of awards and distinctions, including the Nobel Prize for Peace in 1979. She died in 1997.

B.
Kofi A. Annan born in Ghana was first elected Secretary General of the United Nations Organization in 1997.
    As Secretary General Mr Annan gave priority to strengthening the Organization's traditional work in the areas of international peace and security, advocating human rights, the rule of law and the universal values of equality, tolerance and human dignity. One of his ideas was "bringing the United Nations closer to the people". The Secretary General also took a leading role in mobilizing the international community in the battle against AIDS, and more recently against the global terrorist threat, especially after the terrorist attacks hit the United States on 11 September 2001. He got the Nobel Prize for Peace in 2001.

C.
Jimmy Carter, the thirty-ninth president of the United States, left office in 1981, a year later became Distinguished Professor of Emory University in Atlanta, Georgia, and founded the Carter Center. The Center addresses national and international issues of public policy. The aim of the Carter Center was to resolve conflict, promote democracy, protect human rights and prevent disease and other problems. Through the Global 2000 programme, the Center began advancing health care and agriculture in the developing world. Jimmy and Rosalynn Carter volunteer one week a year for Habitat for Humanity, a nonprofit organization that helps needy people in the United States and in other countries renovate and build homes for themselves. He was awarded the Nobel Prize for Peace in 2002.

D.
Wangari Maathai was born in Kenya in 1940. She became the first woman in East and Central Africa to earn a doctorate degree. Professor Maathai got her degree in Biological Science.
    Wangari Maathai was active in the National Council of Women of Kenya. It was while she served in the National Council of Women that she introduced the idea of planting trees in order to conserve the environment and improve the quality of life for many people. Through the Green Belt Movement she assisted women in planting more than 20 million trees on their farms and around schools and churches. Dr Wangari Maathai is internationally recognized for her persistent struggle for democracy, human rights and environmental conservation. She became a Nobel Peace Prize Laureate in 2004.