Bài IV (3,0 điểm) Từ điểm A ở ngoài đường tròn (O; R) vẽ hai tiếp tuyến AB, AC (B, C là các tiếp điểm) và cát tuyến ADE thuộc nửa mặt phẳng bờ là đường thẳng OA không chứa điểm B của đường tròn (O). Gọi H là giao điểm của OA và BC. 1. Chứng minh bốn điểm A, B, O, C cùng thuộc một đường tròn. 2. Chứng minh AO  BC tại H và AH.AO = AD.AE. 3. Đường thẳng đi qua điểm D và song song với đường thẳng BE cắt AB, BC lần lượt tại I, K. Chứng minh tứ giác OHDE nội tiếp và D là trung điểm của IK.

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giúp mình bài này với Test 6 Exercise:Complete tag questions 1.She is collecting stickers, ? 2.We often watch TV in the afternoon, ? 3.You have cleaned your bike, ? 4.John and Max don't like Maths, ? 5.Peter played handball yesterday, ? 6.They are going home from school, ? 7.Mary didn't do her homework last Monday, ? 8.He could have bought a new car, ? 9.Kevin will come tonight, ? 10.I'm clever, ? 11.He's not coming, ? 12.I'm not late, ? 13.The bank lent him the money, ? 14.You shouldn't do that, ? 15.You don't take sugar in coffee, ? 16.She looks tired, ? 17.There's a cinema near the station, ? 18.He arrived late, ? 19. Nobody has arrived yet, ? 20.It's time to go, ? 21. I'm right, ? 22.You had seen it before, ? 23.Everybody looked so miserable, ? 24.You wouldn't do that, ? 25.He'll be there, ? 26.Everybody will be there, ? 27.She's had too much to do lately, ? 28.It won't happen, ? 29.They should be here soon, ? 30.I'm not intruding, ? 31.Nobody's got to leave early, ? 32.That dog's very noisy, ? 33.You have got to arrive before half past eight, ? 34.They took it, ? 35.That's the shop where you used to work, ? 36.The book's a best-seller, ? 37.You haven't got a sister, ? 38.I'm in trouble, ? 39.You would tell me if you knew, ? 40.You'd rather not tell me, ? 41.Lima is the capital of Peru, ? 42.He'd better try harder, ? 43.There's nothing on TV tonight, ? 44.That's the guy who was on TV the other night, ? 45.That's the guy that won the pools, ? 46.She won't be here for another hour, ? 47.Mr McGuinness is from Ireland, ? 48.The car isn't in the garage, ? 49.You are John, ? 50.She went to the library yesterday, ? 51.He didn't recognize me, ? 52.Cars pollute the environment, ? 53.Mr. Pritchard has been to Scotland recently, ? 54.The trip is very expensive, ? 55.He won't tell her , ? 56.He sometimes reads the newspaper, ? 57.You are Indian, ? 58.Peggy didn't use the pencil, ? 59.Mary has answered the teacher's question, ? 60.The boy is from Turkey, ? 61.Sue wasn't listening, .? 62.Andrew isn't sleeping, ? 63.Tom and Maria will arrive at Heathrow, ? 64. He's been to Texas, ? 65.Dogs like meat, ? 66.There are some apples left, ? 67.I'm late, ? 68.Let's go, ? 69.Don't smoke, ? 70.He does sing in the bathroom, ? 71.He'll never know, ? 72.I think, he's from India, ? 73.Lovely day today, ? 74.I'm clever, ? 75.Murat gets up late, ? 76.You didn't go to school yesterday, ? 77.I am not a nurse, ? 78.She doesn't cook well, ? 79.You can speak English, ? 80.I am your best friend, ?