Answer:
a is false (sorry I don't know the other ones)
Explanation:
0.2 as a percentage is 20%
some of the countries that use the federal system are...
United states
Mexico
Germany
Canada
Australia
and Brazil
The fall of Constantinople began with capture of the Byzantine empire's capitol by an invading Ottoman army. This downfall took place May 29, 1453, and is believed to mark the end of the Medieval period. The conquest of Constantinople also greatly impacted Christiandom, as the Muslim Ottoman armies were left unchecked.