.Key Code 4 – Lesson Select. KeyCode 4 - Unit 1KeyCode 4 - Unit 2KeyCode 4 - Unit 3KeyCode 4 - Unit 4KeyCode 4 - Unit 5KeyCode 4 - Unit 6KeyCode 4 - Unit 7KeyCode 4 - Unit 8KeyCode 4 - Unit 9KeyCode 4 - Unit 10