Repairs Supplementing the provisions of Article 4 of this lease: ------- Owner shall maintain and repair the public portions of the Building, both exterior and interior (excluding the exterior and interior of all windows, plate glass, showcases, doors, door frames and bucks). Tenant, throughout the term of this lease, shall take good care of the demised premises, the fixtures and appurtenances therein (including, without limitation, the sprinkler system and any other equipment installed y Tenant in accordance with the provisions of Article 29 hereof, and all installations required for the furnishing to the demised premises of the services enumerated in Article 51 hereof), and the store front and entrance doors thereto and, at Tenant's sole cost and expense, shall clean the sidewalks and curbs adjacent to the demised premises and make all non- structural repairs thereto and to the demised premises (including the exterior and interior of all windows, plate glass, showcases, doors, door frames and bucks) as and when needed to preserve the same in good working order and condition. Notwithstanding the foregoing, all damage or injury to the demised premises or to any other part of the Building, or to its fixtures, equipment and appurtenances, or to the sidewalks or curbs adjacent to the demised premises, whether requiring structural or non-structural repairs, caused by or resulting from (i) the moving of Tenant's fixtures, furniture and equipment or (ii) any act, omission, neglect or improper conduct of, or alterations made by, Tenant, Tenant's servants, employees, invitees or licensees, shall be repaired promptly, either by Owner at Tenant's sole cost and expense, or, at Owner's option, by Tenant at Tenant's sole cost and expense, to the satisfaction of Owner. All the aforesaid repairs shall be of a quality or class equal to the original work or construction and shall be made in accordance with the provisions of Articles 3 and 49 hereof. If Tenant, within 20 days following written notice by Owner, fails to commence the performance of any repairs required to be made by Tenant hereunder or if Tenant thereafter fails to diligently prosecute the performance of such repairs to full completion, the same may be made by owner, and the expenses thereby incurred by Owner shall be collectible as Additional Charges. Tenant shall give Owner prompt notice f any defective condition in any mechanical, electric, sanitary, plumbing, utility or other service system (or any part thereof) located in, servicing or passing through the demised premises and Owner shall thereafter repair such condition, subject, however, to the further provisions of this lease. The water and wash closets and other plumbing fixtures shall not be used for any purposes other than those for which they were designed or constructed, and no sweepings, rubbish, rags, acids or other substances shall be deposited therein.