Every licensee under this article shall:
(a) Permit all reasonable inspections of his business and examinations of his books by public authorities so authorized by law.
(b) Ascertain and at all times comply with all laws and regulations applicable to such licensed business.
(c) Avoid all illegal, improper or unsanitary practices or conditions which do or may affect the public health, morals or welfare.
(d) Refrain from operating the licensed businesses on premises after expiration of his license and during the period his license is revoked or suspended.
(1969 Code §14-19)