Lesson One 1
Lesson Two 9
Lesson Three 18
Lesson Four 27
Lesson Five 35
Test Paper（Lesson 1—5） 43
Lesson Six 56
Lesson Seven 65
Lesson Eight 72
Lesson Nine 82
Lesson Ten 91
Test Paper（Lesson 6—10） 100
Lesson Eleven 115
Lesson Twelve 122
Examination Paper 130
练习题参考答案 144