Do revision in Power Drill
 

You can re-do practices in the previous levels in Power Drill.
 
1. Click/Tap the “Power Drill” tab.
2.
Click/Tap the boxes with number to open the exercises. (New level of Power Drill will be unlocked once you have promoted to that level.)

 
3.
The exercise of the level you selected will be opened. Click/Tap "Start" to do the drills for review and improvement.