Giúp e bài này nha HSG, CHuyên gia Cho m,n thuộc Z+ thỏa mãn $\sqrt{23}$ -$\frac{m}{n}$ >0 CMR $\sqrt{23}-\frac{m}{n} > \frac{4(\sqrt{23-4)}}{mn}$

Làm hộ mk bài 4 nhé mk cảm ơnnn

Tính thể tích khí có (đktc) cần dùng để tác dụng hết với hỗn hợp gồm 0,12 mol CuO và 0,1 mol Fe2O3

Chọn True hoặc False: Robotic engineers are designing the next generation of robots to look, feel and act more human, to make it easier for us to warm up to a cold machine. Realistic looking hair and skin with embedded sensors will allow robots to react naturally in their environment. For example, a robot that senses your touch on the shoulder and turns to greet you. Subtle actions by robots that typically go unnoticed between people, help bring them to life and can also relay non verbal communication. Artificial eyes that move and blink. Slight chest movements that simulate breathing. Man made muscles to change facial expressions. These are all must have attributes for the socially acceptable robots of the future. 1. The generation of human-like robots have been designed recently. T or F 2. People still like cold machines more than this new generation of robots. T or F 3. Robots of the new generation have hair, skin and eyes nearly like humans. T or F 4. These robots don't know how to greet you when you touch their shoulder. T or F 5. Expressions on the faces of these robots are unchanged. T or F

Giúp mình với mình vote cho 5 sao câu C

21. We ............ (live) in the city most of the year. 22. My kids ............. (play) in the garden now. 23. Some people ........... (wait) to talk to you. 24. Lorie............  (travel) to Paris every Sunday. 25. I .......... (bake) cookies twice a month. 26. Selena............  (not drink) tea now. 27. I .......... (vacuum) the carpet right now. 28. She ............. (help) the kids of the neighborhood. 29. My son ............ (talk) on the phone right now. 30.  .......... (you / sleep) now? 31. Jason ............ (do) his homework at the moment. 32. My wife ................ (not cook) today. 33.  ................ (Lucas / study) for his exam right now? 34. I ............... (wash) my face at the moment. 35. John rarely ............... (leave) the country. mn giúp e nốt ạ

Tính: 1 + 2 + 3 + ... + 1998 + 2020

vẽ con gà đeo mắt kính đen mặc áo vét, cánh cầm súng lục chân mang nhẫn

chọn đáp án đúng và giải thik giúp mình nhé

Cho hình thang vuông ABCD có cạnh bên AD vuông góc với đáy. Gọi M, N lần lượt là trung điểm các đường chéo AC, BD. Chứng minh góc NAC= gócMDB. Giúp em với ạ