四部曲

例句：

1. 1. The play is divided into four acts, each with its own distinct plot.
   这部戏剧被分为四个部分，每个部分都有其独特的情节。
2. 2. The composer composed a symphony in four movements.
   这位作曲家创作了一部由四个乐章组成的交响曲。
3. 3. The novel is divided into four parts, each exploring different themes.
   这部小说被分为四个部分，每个部分探讨不同的主题。