Unit 1 Advertisement
Unit 2 Education
Unit 3 Technology
Unit 4 Art
Unit 5 Story
Unit 6 Social Service
Unit 7 Social Manner
Unit 8 School life
Unit 9 Environment
Unit 10 Emotion
Unit 11 Travel
Unit 12 Animals Protection
Unit 13 Invention
Unit 14 Health
Unit 15 Anecdotes and news
Unit 16 People
Unit 17 The influence of technology
Unit 18 Transportation
Unit 19 Life
Unit 20 Energy
Unit 21 Friendship
Unit 22 Social culture
Unit 23 Economy
Unit 24 Family Story
Unit 25 Others
答案与解析
