Geology: What name is given to the point where a river starts ?

Questions

Trivia : Which Japanese suicide technique translates to the English "belly cutting"?

Trivia : Which artificial fiber was invented in 1938?

Trivia : Which bird became extinct in 1861?

Trivia : Which breed of dog has a name derived from the old name for Greece?

Trivia : Which brothers built a home-made supercomputer to calculate the digits of Pi ?