Why were westerners unable to travel by land from europe to asia in the 14th century

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

    which of the following was anecological  result of european exploration from 1400 to 1800?   a.  increased trade with east asia      b.  the spread of epidemic diseases      c.  expansion of english territory      d.  the spread of christianity

What did afolf hitler name his german empire?