[Solved] Lamellae are cracks in the surface of enamel and are visible to the naked eye. GDP: Gross Domestic Product, a measure of the economic performance of a country, calculated by adding the total value of all goods and services produced within its borders over a specific time period. Domestic Output: The total value of goods and services produced within a country's borders in a specific time period. GDP: Gross Domestic Product is the sum market value of all final goods and services produced domestically in a country within a specific period. Foreign Students: Students who pursue their education in a country different from their country of citizenship, often for higher education.