Section 69F. Any town which has accepted the provisions of sections sixty-nine C to sixty-nine F, inclusive, may, after the expiration of three years from the date of such acceptance, upon petition of ten per cent of the qualified voters of the town filed with the selectmen at least sixty days before an annual town meeting, vote at an annual meeting to revoke such acceptance, and the question of such revocation shall be submitted to the voters in the form of the following question:—”Shall the acceptance by the town of sections sixty-nine C to sixty-nine F, inclusive, of chapter forty-one of the General Laws providing for the establishment of a board of public works exercising the powers of certain other departments and town officers be revoked?” If a majority of the votes cast in answer to said question is in the affirmative, then at the next annual town election held after said vote to revoke, the town shall elect such officers as are necessary to exercise and perform the powers, rights and duties transferred to the board of public works by said sections. Such action shall not affect any contract or liability then created or existing. All general laws respecting town administration and town officers, and any special laws relative to said town, the operation of which has been suspended or superseded by the acceptance of said sections sixty-nine C to sixty-nine F, inclusive, shall then be in full force and effect. Any by-law inconsistent with such special or general laws shall be revoked thereby. Any subsequent vote to revoke the acceptance of said sections shall not be taken more often than once in three years.