Cho ΔABC vuông tại A, đường cao AH. Trên tia BC lấy D sao cho BD=BA. Đường vuông góc với BC tại D cắt AC ở E .Chứng minh a, BE là đường trung trực AD b, AD là tia phân giác của góc HAC c, HD < CD

Viết chương trình nhập vào một mảng A gồm n số nguyên và nhập thêm vào một số nguyên x. Hãy kiểm tra xem phần tử x có nằm trong mảng A hay không?

Cho 62,4g dung dịch gồm phenol, rượu etylic có lẫn nước tác dụng với kim loại Na thu được 11,2l khí (đktc). Nếu cho hh trên tác dụng với 200ml dung dịch NaOH 2M thì vừa đủ a) Tìm %m mỗi chất trong hh b) Suy ra C% của phenol

1) Thời gian từ bây giờ đến nửa đêm bằng 3/4 thời gian từ 10 giờ sáng đến 7 giờ tối .Hỏi bây giờ là mấy giờ???

Choose the correct direct speech for the given reported speech. Chọn dạng trực tiếp đúng của các câu gián tiếp cho sẵn. 1. She asked us if we had had any space exploration. A. "Have you had any space exploration?", she asked. B. "Have you made any space exploration?", she asked. C. "Did you had any space exploration?", she asked. 2. They asked if I would be going on another voyage the following month. A. "Will you be going on another voyage this month?", they asked. B. "Will you going on another voyage next month?", they asked. C. "Will you be going on another voyage next month?", they asked. 3. Mandy wanted to know what Mark had been doing in the labratory at 9 a.m the day before. A. "What did you do in the labratory at 9 a.m yesterday, Mark?", Mandy asked. B. "What were you doing in the labratory at 9 a.m yesterday, Mark?", Mandy asked. C. "What were you doing in the labratory at 9 a.m the day before, Mark?", Mandy asked. 4. Our teacher asked if we understood the lesson about planets in solar system that day. A. "Do you understand the lesson about planets in solar system?", our teacher asked. B. "Do you understand the lesson about planets in solar system that day?", our teacher asked. C. "Do you understand the lesson about planets in solar system today?", our teacher asked. 5. Hoa asked if I knew how to change questions into reported speech. A. "Do you know how to change questions into reported speech?", Hoa asked. B. "Are you know how to change questions into reported speech?", Hoa asked. C. "Did you know how to change questions into reported speech?", Hoa asked. 6. Lily asked his father how far she could travel in a spaceship. A. "How far could I travel in a spaceship, dad?", Lily asked. B. "How far can I travel in a spaceship, dad?", Lily asked. C. "How far I could travel in a spaceship, dad?", Lily asked. 7. He asked me how many members there were in my trekking team. A. "How many members are there in your trekking team?", he asked. B. "How many members there are in your trekking team?", he asked. C. "How many members were there in your trekking team?", he asked. 8. She asked me why I hadn't phoned her 2 days before. A. "Why did you phone me 2 days ago?", she asked. B. "Why didn't you phoned me 2 days ago?", she asked. C. "Why didn't you phone me 2 days ago?", she asked. 9. Minh asked me what the differences between Earth and Neptune were. A. "What are the difference between Earth and Neptune?" Minh asked me. B. "What are the differences between Earth and Neptune?" Minh asked me. C. "What were the differences between Earth and Neptune?" Minh asked me. 10. Khanh's mother asked if he wanted to become an astronomer. A. "Do you want to become an astronomer, Khanh?", his mother asked. B. "Did you want to become an astronomer, Khanh?", his mother asked. C. "Are you want to become an astronomer, Khanh?", his mother asked. Submit

Giãi thich chi tiet cho em nha,

Góc mở sớm đóng muộn có tác dụng gì v mọi người (công nghệ 11 nha)

Vietnam’s New year is celebrated according to the Lunar calendar. It is official known as Tet Nguyen Dan, or Tet. It begins between January twenty first and February nineteen. The exact date changes from year to year. Vietnamese people usually make preparations for the holiday several weeks beforehand. They tidy their houses, cook special food, clean and make offerings on the family altars. On the New Year’s Eve, people sit up to midnight to see the New Year in, Then they put on new clothes and give one another the greetings of the season. Tet lasts five days. The first three days are the most important. Vietnamese people believe that how people act during those days will influence the whole year. 1)Is Tet celebrated according to the Lunar calendar? 2)how long tet last ? 3)are the first three days the most important? 4)how do vietnamese people belive ?

Đốt cháy 3,1 gam Photpho trong oxi a, Viết phương trình b Tính khối lượng của sản phẩm c Tính thể tích oxi cần dùng trong điều kiện tiêu chuẩn cho sản phẩm tạo thành tác dụng với 3,6 g nước tính khối lượng axit sinh ra

kinh tế nước ta dưới triều nguyễn ( nửa đầu thế kỉ 19 )