LESSON ONE 1
LESSON TWO 9
LESSON THREE 17
LESSON FOUR 26
LESSON FIVE 33
LESSON SIX 39
SELF-TEST FOR LESSON 1—LESSON 6 44
LESSON SEVEN 54
LESSON EIGHT 60
LESSON NINE 67
LESSON TEN 75
LESSON ELEVEN 81
LESSON TWELVE 89
SELF-TEST FOR LESSON 7—LESSON 12 97
期终试题（Ⅰ） 110
期终试题（Ⅱ） 122
Key to the Exercises of Lesson One 135
Key to the Exercises of Lesson Two 136
Key to the Exercises of Lesson Three 137
Key to the Exercises of Lesson Four 139
Key to the Exercises of Lesson Five 140
Key to the Exercises of Lesson Six 142
Key to the Exercises for Self-test in Lessons 1—6 143
Key to the Exercises of Lesson Seven 144
Key to the Exercises of Lesson Eight 145
Key to the Exercises of Lesson Nine 146
Key to the Exercises of Lesson Ten 147
Key to the Exercises of Lesson Eleven 148
Key to the Exercises of Lesson Twelve 149
Key to the Exercises for Self-test in Lessons 7—12 151
期终试题（Ⅰ）参考答案 152
期终试题（Ⅱ）参考答案 155
编后 159