Can someone give me an example of a topic sentence? can i introduce it with a hook to engage my readers?

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