There were many factors that allowed the Byzantine Empire to last a 1000 years after the end of the Roman Empire which include the fact that Constantinople, the capital of the Byzantine Empire, was protected with walls that lasted almost the entire 1000 years, making Constantinople, and the center of the empire's economy/culture impervious to invaders.
Answer:
for answering other peoples questions in the top left corner there should be a drop down where you can change the grade preference and the subject!
and when you ask a question they should let you choose the subject before you ask.
The second answer is correct (B).
The entrance of the USA in the first world war occurred in April of 1917, when the United States declared war against the Germans and their allies. A large volume of soldiers, tanks, ships and warplanes were used to ensure that the Entente victory was secured. In a short time, the German and Austrian troops were defeated. In November 1918, the armistice of Compiègne hit the retreat of the Germans and the rapid victory of the Triple Entente.
