Answer:
Americans worked harder and were willing to work longer hours.
Explanation:
D.
The rest seem wrong.
It could be B though
A military action the added territory in the United States in 1848 was the Treaty of Guadalupe Hidalgo. It ended the Mexican-American war and added the territories California, Arizona, Colorado, New Mexico, Nevada, Utah, and Wyoming.
Answer:
Explanation:
The murder of Archduke Franz Ferdinand outraged Austria-Hungary. ... Austria-Hungary was furious and, with Germany's support, declared war on Serbia on July 28. Within days, Germany declared war on Russia—Serbia's ally—and invaded France via Belgium, which then caused Britain to declare war on Germany.