Ted Talks has hundreds of talks on every topic by adults and teenagers, and even children. You can choose the topic, the language, whether you want to watch it with or without subtitles... It is a great site to practice your English. Here is an example:
Your Next Read... Number the Stars
, by American writer Lois Lowry, tells the story of ten-year-old Annemaries Johansen and her best friend Ellen Rosen. The events take place in 1943, during the German occupation of Denmark.
In 1943 Hitler planned to arrest and deport Danish Jews. With the help of the Danish Resistance movement and many ordinary Danish people, 7, 220 of Denmark's 7,800 Jews were evacuated to Sweden.