What event in 1939 caused Britain and France to declare war on Germany, starting WWII? A Germany took control of Austria.
B Germany rebuilt its military.
c) Germany persecuted Jews.
D Germany invaded Poland.

Which of the following describes an effect of world war ll on the united states economy a. automobile companies produced a record number of cars b. many factories had to expand to produce military equipment c. the airplane industry suffered as the allies began using airplanes in combat d.cities with shipyards declined because so many ships had been sent overseas.