Jan Evangelista Purkinje made the important _____________ that everybody's fingerprints are different in 1823.

In the Middle AGes the Italians had a ________ exchange of metal and oil for paper from Egypt.

The first moon landing was in 1969. What will the future of space ________ be?

Millions of people died in the flu in 1918. The disease ________ very fast.

Before the ___________of more complex forms of wheeled transportatio and roads people used to walk and ride horses on paths.

Countries sometimes go to ______ when they fight over land, religion and resources.

Since it's _______ in 1946, Unicef has helped millions of children worldwide.

Robert NOyce was an electrical engineer whose most famous ______ was the microchip.

US president Abraham Lincoln was against slavery and slave _______.

Albert Einstein was a famous physicist but he also campaigned against fighting and ________

There is fighting among countries; but some people believe world ___________ is possible.

Polish scientist Marie Curie was behind the _________ of hospital x-rays.

Mahadma Ghandi was the leader for Indian Independence. He believed in nonviolence and ________.

Rosalind Franklin was a british chemist. She contrubuted to the ________ of the structure of DNA: