Answer:
B. National conventions include speeches from party leaders and invited guests.
C. National parties adopt official platforms at conventions.
Step-by-step explanation:
B. National conventions include speeches from party leaders and invited guests.
C. National parties adopt official platforms at conventions.
The two key elements of national party conventions are speeches from party leaders and invited guests, as well as the adoption of official party platforms. The speeches provide a platform for party leaders to articulate their vision and goals, while the party platforms provide a more detailed outline of the parties' plans and objectives. These two elements provide a comprehensive overview of each party and are essential to the functioning of the national party conventions.