https://preparationpoint.info/solved-past-papers-mcqs/ppsc-past-papers/ppsc-past-papers-2018/model-paper-65-excise-taxation-inspector-bs-16-2018-region/when-no-tariffs-are-imposed-on-all-imports-and-exports-it-is-called/
When no tariffs are imposed on all imports and exports ,it is called :