Must the concept of ‘medicament' within the meaning of heading 3004 of the Combined Nomenclature be interpreted as also including food preparations such as the products at issue, which are intended exclusively to be administered enterally (by means of a stomach tube) under medical supervision to persons who are undergoing medical treatment for a disease or ailment and who have the product administered to them as part of the control of that disease or ailment in order to control or prevent malnutrition? Must the concept of ‘beverages' within the meaning of heading 2202 of the Combined Nomenclature be interpreted as including liquid foodstuffs such as the products at issue, which are not intended to be drunk but to be administered enterally (by means of a stomach tube)?