Unit 1 1
Part Ⅰ Text Exercises 1
Part Ⅱ Exercises for PRETCO 10
Unit 2 19
Part Ⅰ Text Exercises 19
Part Ⅱ Exercises for PRETCO 27
Unit 3 36
Part Ⅰ Text Exercises 36
Part Ⅱ Exercises for PRETCO 45
Unit 4 53
Part Ⅰ Text Exercises 53
Part Ⅱ Exercises for PRETCO 63
Test yourself(for Units 1-4) 72
Unit 5 80
Part Ⅰ Text Exercises 80
Part Ⅱ Exercises for PRETCO 90
Unit 6 98
Part Ⅰ Text Exercises 98
Part Ⅱ Exercises for PRETCO 106
Unit 7 115
Part Ⅰ Text Exercises 115
Part Ⅱ Exercises for PRETCO 124
Unit 8 132
Part Ⅰ Text Exercises 132
Part Ⅱ Exercises for PRETCO 140
Test yourself(for Units 5-8) 149
Test yourself(for PRETCO—Level A) 157