Chú cháu làm cái bài này với cháu không biết Cháu cảm ơn các cô các chú ạ

Giải hộ gấp!!! Ai nhanh em cho hay nhất!!!

tại ba đỉnh A B C của hình vuông cạnh a trong chân không đặt ba điện tích dương q xác định cường độ điện trường a, tại tâm O hình vuông b, tại D Giúp mình với đang cần gấp :((

Nếu một hình chữ nhật có diện tích là 60 cm2 và có đường chéo bằng 13 cm thì chu vi là

`a) A=3-3^2+3^3-3^4+.......+3^2019-3^2020 ` `b) B=1-3+5-7+9-11+......+2013-2015`

Giải thích vì sao lại viết như thế GRAMMAR MULTIPLE CHOICE: 1. As soon as Martina saw the fire, she ______ the fire department. A. was telephoning B. telephoned C. had telephoned D. has telephoned 2. Jane’s eyes burned and her shoulder ached. She ______ at the computer for five straight hours. A. is sitting B. has been sitting C. was sitting D. had been sitting 3. The man who sat beside me on the plane _____ nervous. He _____ by air before. A. looked/ has never traveled B. looked/ had never traveled C. was looking/ never traveled D. looked / was never traveling 4. The Second World War _______ in 1939 and _______ in 1945. A. begins/ ends B. had begun / ended C. began/ had ended D. began /ended 5. It seems that whenever I travel abroad, I _______ to take something I need. A. forgot B. am forgetting C. forget D. had forgotten 6. I _______ Casablanca for the first-time last night. I _______ it before. A. saw /had never seen B. see /have never seen C. have seen /never saw D. was seeing /had never seen 7. Yesterday Ann introduced me to her husband. As I saw him, I ______ that I ______ him before. We went to primary school together. A. knew / met B. had known / had met C. knew /had met D. had known / met 8. I _______ you sooner if someone _______ me you were in the hospital. A. would visit / told B. will visit /tells C. had visited / would have told D. would have visited / had told

cho tứ giác ABCD (AB=AC)phân giác BD ,BE CMR tứ giác BDCE là hình gì ? vì sao CMR BE=ED=DC biết góc A=50.tính các góc của tứ giác BEDC vẽ hình giúp mình với mình hứa sẽ vote 5 sao và ctlhn

Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

tại sao thức ăn trong cơ thể trùng giày luôn di chuyển

mọi người giúp em trong hôm nay ạ