Hi, I've just signed up to Popupchinese and am currently taking language classes which are geared towards preparation for the HSK level 2 and 3 exams. The problem is that as we do not use any particular textbook in class, I'm finding it difficult to prepare for classes in advance or do more in-depth related study afterwards.

Does anyone know what are the best textbooks or prep material which follow the curriculum for HSK level 3?

Thank you.