Final answer:
Isaac and Rebekah's narratives mark a bridge between the longer stories of Abraham-Sarah and Jacob-Leah.
Step-by-step explanation:
The two characters and their narratives that mark a bridge between the longer stories of Abraham-Sarah and Jacob-Leah are Isaac and Rebekah. In the story of Isaac and Rebekah from Genesis, Isaac is the son of Abraham and Sarah, and Rebekah is the wife chosen for Isaac by God through intervention. Their narrative connects the previous generation of Abraham and Sarah to the next generation of Jacob and Leah.