The arch is the name by which a type of semicircular structure is known, which is used as a support for buildings because it provides great stability to them, due to the distribution of the load that allows it to support large amounts of weight. This form of architecture developed in ancient civilizations like Mesopotamia. However, its greatest use was in ancient Rome, where it was used in different structures with domestic functions such as sewers, aqueducts and bridges; and larger buildings such as theaters and the monumental Roman Coliseum. So, the correct answer is C. Arches.
The European Union is one of the world's most open economies.
The EU is also the largest single market in the world.
Free trade between Member States is one of the fundamental principles of the EU, so the EU is also committed to liberalizing world trade.
From 1999 to 2010, EU external trade doubled and now accounts for more than 30% of EU gross domestic product (GDP). The EU is responsible for Member States' trade policies and negotiates agreements with them. In international trade negotiations, the EU's single appearance has more influence than individual Member States.
