Switching between levels.

I recently completed all Level 4 writing passages, and now have to repeat previously answered passages and questions. Although this can be beneficial for some people, I would prefer to practice with passages from other levels. Currently, the only way to do this is to purposefully get questions wrong that your skill level will go down.

It would be really useful if there is an option to switch between questions in different difficulties, especially in the Reading and Writing sections where questions tend to get the most repetitive.