The transcripts are in the back of the Arbeitsbuch. Read along while listening – that itself acts as an answer key.
The Complete Guide to Menschen B1.2 Lösungen – Where to Find Answers & How to Use Them Effectively
Use a B1 grammar reference (e.g., Schubert Grammatik B1 or online resources like Deutsch-lernen.com ). Many workbook exercises are standard B1 patterns.