geography: In which continent would you find the Amur river ?

Questions

While the world was busy welcoming the arrival of the twentieth century on December 31, 1900, a forceful gale on England's Salisbury Plain blew over one of the ancient monumental stones at ---------------?

After the U.S. Civil War, Iowa was the first state to give the vote to -----------------.?

------------------ became the first woman to receive a diamond engagement ring. It was given to her by Maximilian I of Germany in 1477.?

At funerals in ancient ------, when the lid of the coffin was closed, mourners took a few steps backward lest their shadows get caught in the box.?

At the height of its power, in 400 B.C., the Greek city of ------ had 25,000 citizens and 500,000 slaves.?