Any person with an interest in the district may join in the petition, move to dismiss the petition, or file an answer to such petition. The provisions of the code of civil procedure respecting motions and answers to a petition shall be applicable to motions and answers to the petition in such special proceedings. The persons filing motions to dismiss and answering the petition shall be the defendants to the special proceedings and the persons filing the petition or joining in the petition shall be the plaintiffs. Every material statement of the petition not specially controverted by the answer shall, for the purpose of the special proceedings, be taken as true. Each person or party in interest failing to answer the petition shall be deemed to admit as true all the material statements of the petition. The rules of pleading and practice provided by the code of civil procedure which are not inconsistent with the provisions of sections 31-727 to 31-770 are applicable to the special proceedings in sections 31-771 to 31-776.