I understand you're looking for the "Menschen B1.1 Arbeitsbuch" (workbook) in PDF format for free. However, I must let you know that sharing direct download links to copyrighted material like this would be illegal in most countries, as the workbook is published by Hueber Verlag, a major German language publisher.
No Immediate Feedback: Without a teacher, learners might memorize without fully understanding nuances. A Note on "Free PDF Downloads" Menschen B1 1 Arbeitsbuch Pdf Free Download
Below is a comprehensive article written for you. I understand you're looking for the "Menschen B1