... YOURSELF C 6 Unit 10 : NATURE IN DANGER 6 Unit 11 : SOURCES OF ENERGY 10 TEST YOURSELF D 13 Unit 12 : THE ASIAN GAMES 14 Unit 13 : HOBBIES 18 TEST YOURSELF E 22 Unit 15 : SPACE CONQUEST 22 Unit 16 : THE WONDERS ... PARTY 11 TEST YOURSELF A 16 Unit 4: VOLUNTEER WORK 16 Unit 6: COMPETITIONS 21 TEST YOURSELF B 26 Unit 7: WORLD POPULATION 26 Unit 8: CELEBRATIONS 31 Unit 9: THE POST OFFICE 1 TEST YOURSELF C 6 Unit ... số động từ không dùng ở thì Present Progressive, mà chỉ dùng ở thì Present Simple: to be, to want, to need, to have (có), to know, to understand, to seem, to feel, to like, to dislike, to hate,...