What was the "spark" that set off world war i?

What does this picture revesl about the the work of peasent women

The sixth amendment of the u.s. constitution guarantees the right to which of the following?

Which of these innovations led to increased production in american factories in the early 1800s? a. the use of interchangeable parts b. the construction of canals c. the invention of the mechanical reaper d. the availability of electricity