The easier it is to maintain a working product or fix a broken product, the more serviceable that product will appear. This also makes sense when you think about the different products which you have used in your life where they each have had different levels of serviceability.
Answer:
wings flap up and down
Explanation:
when they fly their wings need air so they can fly
The Allies included Britain, France, Russia, Italy and the United States. These countries fought against the Central Powers which included Germany, Austria-Hungary, Ottoman Empire and Bulgaria. Archduke Ferdinand, of Austria-Hungary, was assassinated by a Serb on June 28, 1914.