The "B1" level corresponds to the intermediate level of German language proficiency according to the Common European Framework of Reference for Languages (CEFR). At this level, learners are expected to have a wide range of language skills, including understanding and using complex sentences, dealing with most everyday situations, and expressing themselves clearly and in detail on familiar topics.
However, if you are looking for the solutions to the or A2 Testheft, or general B1 materials, here is how you can find them: studio 21 b1 testheft losungen
Check the "Lösungen" to see if you consistently miss specific grammar points (e.g., Passiv or Nebensätze ). The "B1" level corresponds to the intermediate level