Xác định CTPT ancol sau: a/ ancol no , đơn chức X có tỉ khối so vớ o2 là 2,25 b/ ancol no , hai chức X có tỉ hối so với hidro là 31

viết i bài văn tả 1 thắng cảnh ở VN bằng tiếng anh hộ em ạ

cho tam giác ABC: D là trung điểm AB; lấy E, F trên bc sao cho: BE = EF = FC. a/ chứng minh: DE//AF b/ CD cắt AF tại G. chứng minh GD = GC

Chọn từ có phần gạch chân và phát âm khác nhau

Với giá trị nào của x thì mỗi căn thức sau có nghĩa Giúp mình với ạ Mình cảm ơn

Phân tích câu thơ Anh đi anh nhớ quê nhà /Nhớ canh rau muống nhớ cà dầm tương(Phân tích ko vt văn)

Calli : Nhất bạn, bạn là nhấttt

I. Rewrite the sentences. Viết lại câu Ex: They were married five years ago. −>They have been married for five years. 1. The last time we saw her was on Christmas day. We haven’t 2. I haven’t eaten this kind of food before. This is 3. It started raining an hour ago. It has 4. We haven’t visited my grandfather for two months. The last time 5. I have studied English for three years. I began 6. My brother hasn’t seen his best friend for nearly five years. It’s 7. When did you start learning English? How long 8. We started living here fifteen years ago. We have 9. The last time she visited me was five years ago. She hasn’t 10. I last wrote to my uncle in July. I haven’t 11. It’s a long time since we became close friends. We have 12. Minh began to collect stamps in 2000. Minh has 13. This is the first time he has gone abroad. He hasn’t 14. She started driving 1 month ago. She has 15. We began eating when it started to rain. We have 16. I last had my hair cut when I left here. I haven’t 17. The last time she met me was 5 months ago. She hasn’t 18. It is a long time since we last met. We haven’t 19. When did you have it? How long 20. This is the first time I’ve had such a delicious meal. I haven’t 21. I haven’t seen him for 8 days. The last 22. I haven’t taken a bath since Monday. It is

Chọn 1 trong 2 bài rồi làm nha bài nào cx dc ạ

3(sin^4 x + cos^4 x) -2 sin^6 x+cos^6 x-1=0