 Complete the following phrase:  The Congresses also provided the party leadership with formal legitimacy by providing a mechanism for the election of new members and the retirement of old members who had lost favor. The elections at Congresses were all predetermined and the candidates who stood for seats to the Central Committee and the Central Auditing Commission were approved beforehand by the Politburo and the Secretariat. A Congress could also provide a platform for the announcement of new ideological concepts. For instance, at the 