Red Label : Unit 4 - Lesson 4 - Exercises 38, 39, 40 + 41
Done? Make the practise more exercises in Lesson 4.
Yellow Label: Unit 4 - Lesson 2 - Exercises 18 + 19, Unit 4 - Lesson 4 - Exercises 31 + 32
Done? Make the practise more exercises in Lesson 4.