1) What century began on January 1, 2001?
2) When did the 21st century begin?
3) How long is a decade?
4) When did the 17th century end?
5) The 19th century began on what date?
6) The 20th century ended with which year?
7) What century began on January 1, 2001 and ended on December 31, 2100?
8) In what century did the American Revolutionary War take place?
9) In what decade did the space race between the US and the Soviet Union begin?
10) During which decade did the Titanic sink?