Unit 1 1
Part Ⅰ Text Exercises 1
Part Ⅱ Exercises for PRETCO 7
Unit 2 15
Part Ⅰ Text Exercises 15
Part Ⅱ Exercises for PRETCO 22
Unit 3 31
Part Ⅰ Text Exercises 31
Part Ⅱ Exercises for PRETCO 40
Unit 4 47
Part Ⅰ Text Exercises 47
Part Ⅱ Exercises for PRETCO 54
Test yourseef (for Units 1-4) 62
Unit 5 72
Part Ⅰ Text Exercises 72
Part Ⅱ Exercises for PRETCO 79
Unit 6 87
Part Ⅰ Text Exercises 87
Part Ⅱ Exercises for PRETCO 95
Unit 7 103
Part Ⅰ Text Exercises 103
Part Ⅱ Exercises for PRETCO 111
Unit 8 118
Part Ⅰ Text Exercises 118
Part Ⅱ Exercises for PRETCO 124
Test yourseef (for Units 5-8) 131