No person shall be eligible to the offices mentioned in Sections 97 and 99 who is not at the time of his election twenty-four years of age (except Clerks of County and Circuit Courts, who shall be twenty-one years of age), a citizen of Kentucky, and who has not resided in the State two years, and one year next preceding his election in the county and district in which he is a candidate. No person shall be eligible to the office of Commonwealth's Attorney unless he shall have been a licensed practicing lawyer four years. No person shall be eligible to the office of County Attorney unless he shall have been a licensed practicing lawyer two years. No person shall be eligible to the office of Clerk unless he shall have procured from a Judge of the Court of Appeals, or a Judge of a Circuit Court, a certificate that he has been examined by the Clerk of his Court under his supervision, and that he is qualified for the office for which he is a candidate.