Final answer:
Acts is a continuation of Luke due to addressing Theophilus in its opening and sharing a consistent writing style and themes with the Gospel of Luke.
Step-by-step explanation:
The question asks for two features that show the Book of Acts is a continuation of the Gospel of Luke. One key feature indicating this continuation is the prologue of Acts, which addresses the same recipient, Theophilus, as the Gospel of Luke, establishing a direct narrative link. Another feature is the consistent writing style and vocabulary between Luke and Acts, along with thematic continuities such as the focus on the Holy Spirit and the expansion of the Christian mission from Jerusalem to the rest of the world, including both Jewish and Gentile populations.