a)vì sao không khí và nước chanh là hỗn hợp? có thể đổi độ chua của nước chanh bằng cách nào? b)người ta trộn rất cẩn thận bột sắt và bột lưu huỳnh rất min , thu được một lọa bột đen.Có thể xem bột đó là hỗn hợp gì

Các câu hỏi liên quan

A. Give the correct form of verbs. 1. Peter ______________very hard. He never gets high scores. (not/ study) 2. My mother often ______________me English on Saturday evenings. (teach) 3. I like Maths but she ______________Literature. (like) 4. My sister ______________dishes every day. (wash) 5. They ______________breakfast every morning (not/ have) 6. The moon ______________ around the earth. (circle) 7. He______________ German so well because he ______________ from Germany (speak)/(come) 8. Mary ______________very well, but she ______________very fast. (swim)/ (not run) 9. How many lessons ______________a day? (she often /have) 10. ______________ Jim and Joe ______________ the flowers every week? (water) B. Put do, don’t, does, doesn’t, am, is, are, have into the gaps. 1. Where ______________you go shopping? 2. I ______________having lunch with my friends now. 3. Now Mai ______________watching a video clip about science. 4. Mr. Minh ______________our favorite teacher. He teaches Science. 5. What ______________you usually do at break time 6. Nam and Duy ______________not doing their homework. 7. We often ______________Maths lessons on Monday. 8. How ______________you go to school every day? 9. ______________you hungry? 10. ______________your brother like pop music? Writing A. Rearrange the sentences to make meaningful sentences 1. fly/ with my parents/ to Florida/ sometimes/ I/ in spring. → 2. late/ comes/ she/ often/ to school/ in winter. → 3. meet/ at the sports ground/ they/ after dinner/ always/ their friends. → 4. enjoys/ swimming/ in our pool/ always/ in the morning/ she. → 5. My grandmother / at home / always / is / in the evening /. → 6. celebrate / my birthday / I / usually / with my friends /. →