Some good points above and interesting ideas. I would probably agree with everyone who has mentioned that paraphrasing would require most processing, though I would argue that ‘learning the passive’ (do we mean simply the form? or various uses, etc) and learning how to reference could also be quite demanding, especially for someone who was new to it.
Agree with @rob’s great ideas on activities and @paul-m’s point that these would need to adhere to the 6 multi media principles. Perhaps with paraphrasing, more open ending activities such as note-making / summarising key points could also help students organise and integrate their knowledge.