Why did people in 1999 believe the world was going to end in the next century?

How did people in the 14th century understand black death

How many people died in battle during world war 1? a. 8-9 mill b. 3-4 mill c. 1 mill d. more than 10 mill

One drawback of voluntary trade is that it a.requires two groups to use a common language b.can make one group dependent upon another for necessary goods c.doesn't occur unless there is a shortage of goods for at least one group d.forces groups to rely on themselves to produce all the goods they need