In the late 1800s, what was the effect of mass production on manufa O Machines quickly made large amounts of product.
O Workers were able to make products by hand.
O Workers needed to have very specific skills.
O Machines slowly made small amounts of product.

the american rail road was the most influential and useful transportation system developed in the 1800's with steam locomotives and in the very late 1800's and early 1900's diesel electric locomotives being used to transport goods and people around the newly expanded united states!

yellow fever and other tropical diseases

the map that was shown mostly had eastern asia highlighted. the answer would mostly likely be "the spread of communism into eastern asia set the stage for the korean war."

hopefully this .

a. poison gas was sprayed over battlefields by airplanes to weaken enemy positions before major attacks.