What is the main idea of the passage? There are several events that can change the earth's surface very quickly. Volcanoes can erupt and spread lava, rock, and ash for several miles. Earthquakes can leave large cracks in the earth's surface. A. Several events can change the earth's surface. B Volcanoes can be dangerous. C. Earthquakes can leave large cracks in the earth's surface.

Identify the trade regulation concept described in each scenario. protectionism free trade trade war country a and country b want to develop their respective export markets. both countries have highly developed agricultural, industrial, and service sectors. the countries decide to initially lower trade barriers and eventually remove them completely. arrowright country a has an agrarian economy with an emerging industrial sector. to allow domestic industries to grow, country a applies quotas on all industrial products except those that are used as resources. arrowright country a passes an economic policy that will indirectly give its own companies an advantage over country b’s companies. country b alleges that the policy violates the countries’ trade agreement and imposes retaliatory tariffs. arrowright