Cheap for all that gold

1.  U.S.A bought Alaska from Russia for 2 cents / acre.
2.  It is legal to duel in Paraguay if you're registered as blood donors.
3.  The bamboo is the world's tallest grass.
4.  If exposed to alcohol, the scorpions will sting themselves to death.
5.  James Garfield, an U.S.A. President was able to write Greek with one hand and Latin with the other... at the same time.
6.  Giraffes can clean their ears with their tongues.
7.  41% of the Moon in never visible from Earth at any time.
8.  The only liquid metal in standard conditions (20°C and 1atm pressure) is mercury.
9.  Cats have 32 muscles in each ear.
10.  Pearls melt in vinegar.