LESSON ONE 1
LESSON TWO 12
LESSON THREE 22
LESSON FOUR 32
LESSON FIVE 43
LESSON SIX 54
SELF-TEST FOR LESSON 1—LESSON 6 61
LESSON SEVEN 75
LESSON EIGHT 82
LESSON NINE 89
LESSON TEN 100
LESSON ELEVEN 109
LESSON TWELVE 118
SELF-TEST FOR LESSON 7—LESSON 12 127
期终试题 138
Key to the Exercises of Lesson One 149
Key to the Exercises of Lesson Two 151
Key to the Exercises of Lesson Three 154
Key to the Exercises of Lesson Four 157
Key to the Exercises of Lesson Five 160
Key to the Exercises of Lesson Six 163
Key to the Exercises for Self-test in Lessons 1-6 166
Key to the Exercises of Lesson Seven 168
Key to the Exercises of Lesson Eight 170
Key to the Exercises of Lesson Nine 172
Key to the Exercises of Lesson Ten 175
Key to the Exercises of Lesson Eleven 177
Key to the Exercises of Lesson Twelve 179
Key to the Exercises for Self-test in Lessons 7-12 182
期终试题答案 183
编后 186