Warehousing bond requirement: importers must execute bonds, furnish prescribed security and ensure payment of duties, interest and penalties. Imposes a warehousing bond obligation on importers assessed to duty: the importer must execute a bond undertaking compliance with the Act, payment of duties and interest as demanded, and payment of penalties; the Commissioner may permit a general bond for multiple imports; prescribed security must also be furnished; bonds remain effective despite transfer to another warehouse; transferees must execute the prescribed bond or approved general bond and furnish required security.