I am doing the same exact test and when i get the answer ill tell you
One of the most significant challenges is building an airplane had to do with "propulsion", since the technology that allowed motors to have enough energy to lift an airplane into the sky with a passenger wasn't available for most of history.
I believe the answer is A a connection with nature.
The United States, Great Britain, and the Soviet Union joined forces to fight the Nazi Germany, Fascist Italy, and Imperial Japan. The United States entered the war. The war ended in a treaty and Germany had to finish paying WWI era repairs.<span />