Dẫn 3,36l khí CO (đo ở đktc) qua ống sứ nung nống đụng 16g CuO, sau một thời gian phản ứng thu được chất rắn B có khối lượng 14,4 g và hỗn hợp khí X. a) Tính hiệu suất phản ứng b) Tính tỉ khối của hỗn hợp khí X so với Hidro

bài 1: 1 chai đựng đầy nước thì nặng 1350g. Nếu đựng 1 nửa nước thì nặng 750g. Hỏi khi chai không đựng nước thì nặng bao nhiêu gam? bài 2: người ta xếp các chữ cá LUATBIENVIETNAM thành 1 dãy LUATBIENVIETNAMLUATBIENVIETNAM..... hỏi chữ cái thứ 2013 là chữ gì?

vẽ cali : Việt nam vô địch vs lá cờ VN và đậu mầm cổ vũ VN nha

2. My father hasn’t smoked cigarettes for a month. A. It’s a month since my father last smoked cigarettes. B. It’s a month ago that my father smoked cigarettes. C. It’s a month that my father hasn’t smoked cigarettes. D. It’s a cigarette that my father smoked a month ago. 3. Having finished their work, the workers expected to be paid. A. The workers expected to be paid because they had finished their work. B. Having their work finished, the workers expected to be paid. C. Having expected to be paid, the workers finished their work. D. Having been finished their work, the workers expected to be paid. 3. Mr. Brown bought this car five years ago. A. Mr. Brown started to buy this car five years ago. B. It has been five years when Mr. Brown bought this car C. Mr. Brown has had this car for five years . D. It is five years ago since Mr. Brown bought this car. 4. I haven’t enjoyed myself so much for years. A. It’s years since I enjoyed myself so much. B. It’s years since I have enjoyed myself so much. C. It was years since I had enjoyed myself so much. D. It has been years since I have enjoyed myself so much. 5. This is my tenth year working in this bank. A. By the end of this year , I will work in this bank for ten years. B. I have worked in this bank for ten years by the end of this year. C. By the end of this year , I will have worked in this bank for ten years. D. I had been working in this bank for ten years by the end of this year. 6. The famous actor was last seen in 2000. A. The famous actor has not been able to see since 2000. B. No one has seen the famous actor since 2000. C. The famous actor didn’t see anyone in 2000. D. No one saw the famous actor until 2000. 7. I came to live here three months ago. A. It was three months since I lived here. B. I’ve been living here for three months. C. I lived here for three months. D. I didn’t live here for three months. 8. She goes to the shops every Friday. A. She goes every day to the shop but not on Friday. B. It’s not Friday, but she’s going to the shops. C. She always goes to the shops on Friday. D. She never goes to the shops on Friday. 9. Michael took a deep breath and dived into the water. A. After Michael had taken a deep breath, he dived into the water. B. Having taken a deep breath, he dived into the water. C. After Michael took a deep breath, he had dived into the water. D. A & B are correct. 10. We started working here three years ago. A. We worked here for three years. B. We have no longer worked here for three years. C. We have worked here for three years. D. We will work here in three years. 11. It’s a long time since we last went to the cinema. A. We have been to the cinema for a long time. B. We haven’t been to the cinema for a long time. C. We don’t go to the cinema as we used to. D. We wish we went to the cinema now. 12. I haven’t finished this book yet. A. I’m still reading this book. B. I have read this book before. C. The book I’m reading hasn’t finished. D. I will read this book some day. 13. He used to jog every morning. A. He enjoys jogging every morning. B. He never fails to jog every morning. C. He doesn’t now jog every morning. D. He intended to jog every morning. 14. I have never felt happier than I do now. A. I felt happier before. B. I feel happy now. C. I have never felt happy. D. I have always felt happy. 15. He last had his eyes tested ten months ago. A. He hasn’t had his eyes tested for ten months . B. He had not tested his eyes for ten months then. C. He had tested his eyes ten months before. D. He didn’t have any test on his eyes in ten months. 16. Someone knocked on the door during my lunchtime. A. I had lunch when someone knocked on the door. B. When I had had lunch, someone knocked on the door. C. I was having lunch when someone was knocking on the door. D. I was having lunch when someone knocked on the door. 17. Steve left before my arrival. A. When I arrived, Steve had already left. B. Steve left as soon as I arrived. C. While Steve was leaving I arrived. D. Steve hadn’t left until I arrived. 18. I haven’t been here before. A. Being here is a pleasant experience. B. This is the first time I have been here . C. I have wished to be here for long. D. Before long I will be here.

Vẽ cái j cổ vũ đội tuyển Việt Nam đi ae ơi

Hnay có ai thức cổ vũ đội tuyển VN k nào??? Vẽ anime/chibi cổ vũ nha K nhận mầm/digi

Mọi người giúp đỡ em ạ em sẽ đánh giá cao cho ạ

Vẽ semi NL: đừng bao giờ tự hào với những gì mình đang có mà lỡ ngủ quên. Bởi có thể có người vẫn đang làm việc một cách thầm lặng mà dần dần vươn lên. Đến lúc ta sực tỉnh ra, nó đã muộn mất rồi Thân !

Tìm min, max của các hàm sau. Cầu trời tìm được nhanh, mình lú luôn với đống bài tập rồiiiiii

A(x) = -1 + 5x6 - 6x2 - 5 - 9x6 + 4x4 - 3x2 B(x) = 2 - 5x2 + 3x4 - 4x2 + 3x + x4 - 4x6 - 7x a) Thu gọn và sắp xếp các số hạng theo thứ tự giảm dần của biến b) Tìm bậc và các hệ số của mỗi đa thức c) Tìm nghiệm của đa thức C(x) = A(x) - B(x)