Cho tam giác ABC vuông tại A. M là điểm di động trên cạnh AC. Từ C kẻ đường thẳng vuông góc với tia BM tại H, cắt tia BA tại O. Chứng minh rằng: a) OA.OB = OC.OH b) góc OHA không đổi c) BM.BH + CM.CA không đổi

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Bài 1: Cho dạng đúng của động từ trong ngoặc ở thì quá khứ tiếp diễn. 1. At this time last year, they (build) this house. 2. I (drive) my car very fast when you called me. 3. I (chat) with my friends while my teacher (teach) the lesson yesterday. 4. My father (watch) TV when I got home. 5. At this time yesterday, I (prepare) for my son’s birthday party. 6. What you (do) at 8 pm yesterday? 7. Where you (go) when I saw you last weekend? 8. They (not go) to school when I met them yesterday. 9. My mother (not do) the housework when my father came home. 10. My sister (read) books while my brother (play) football yesterday afternoon. Bài 2: Use your own ideas to complete the sentences.Use the past continuous 1 Matt phoned while we ………….. 2 The doorbell rang while I ………. 3 We saw an accident while we ………. 4 Ann fell asleep whiel she ………. 5 The television was on, but nobody ………. Bài 1: Cho dạng đúng của động từ trong ngoặc: 1. They (do) it for you tomorrow. 2. My father (call) you in 5 minutes. 4. We believe that she (recover) from her illness soon. 5. I promise I (return) school on time. 6. If it rains, he (stay) at home. 7. You (take) me to the zoo this weekend? 8. I think he (not come) back his hometown. Bài 2: Dùng từ gợi ý viết thành câu hoàn chỉnh. 1. She/ hope/ that/ Mary/ come/ party/ tonight. ………………………………………………………………………… 2. I/ finish/ my report/ 2 days. ………………………………………………………………………… 3. If/ you/ not/ study/ hard/,/ you/ not/ pass/ final/ exam. ………………………………………………………………………… 4. You/ look/ tired,/ so/ I/ bring/ you/ something/ eat. ………………………………………………………………………… 5. you/ please/ give/ me/ lift/ station?.............................................. Bài tập 1: Chọn đúng thì của các câu sau (quá khứ đơn và quá khứ tiếp diễn): 1. Alice saw/ was seeing the accident when she was catching the bus. 2. What were you doing/ did you do when I called? 3. I didn’t visit/ weren’t visiting my friends last summer holiday. 4. It rained/ was raining heavily last July. 5. While people were talking to each other, he read/ was reading his book. 6. My sister was eating/ ate hamburgers every weekend last month. 7. While we were running/ ran in the park, Mary fell over. 8. Did you find/ Were you finding your keys yesterday? 9. Who was she dancing/ did she dance with at the party last night? 10. They were watching/ watched football on TV at 7 p.m. yesterday. Bài tập 2: Hoàn thành các câu sau sử dụng thì quá khứ đơn và quá khứ tiếp diễn: 1. Where/ you/ go? 2. Who/ you/ go with? 3. How/ you/ get/ there? 4. What/ you/ do/ during the day? 5. you/ have/ a/ good/ time? 6. What/ your parents/ do/ while/ you/ go/ on holiday? Bài tập 3: Chia đúng các động từ sau ở thì quá khứ đơn và quá khứ tiếp diễn: In my last holiday, I went to Hawaii. When I (go) (1) …………to the beach for the first time, something wonderful happened. I (swim) (2) …………in the sea while my mother was sleeping in the sun. My brother was building a sand castle and my father (drink) (3) …………. some water. Suddenly, I (see) (4) …………a boy on the beach. His eyes were blue like the water in the sea and his hair (be) (5) …………beautiful black. He was very tall and thin and his face was brown. My heart (beat) (6) …………fast. I (ask) (7) …………him for his name with a shy voice. He (tell) (8) …………me that his name was John. He (stay) (9) …………with me the whole afternoon. In the evening, we met again. We ate pizza in a restaurant. The following days we (have) (10) …………a lot of fun together. At the end of my holiday when I left Hawaii I said goodbye to John. We had tears in our eyes. He wrote me a letter very soon and I answered him. Bài tạp 4: Chia động từ ở thì quá khứ tiếp diễn 1. I ___________________down the street when it began to rain (go) 2. At this time last year, I ___________________an English course (attend) 3. Jim ________________ under the tree when he heard an explosion (stand) 4. The boy fell and hurt himself while he _________________ a bicycle (ride) 5. When we met them last year, they______________ in Santiago (live) 6. The tourist lost his camera while he________________ around the city (walk) 7. The lorry _______________ very fast when it hit our car (go) 8. While I ____________________in my room, my roommate ___________________ a party in the other room (study/ have) 9. Mary and I___________________ the house when the telephone rang (just leave) 10. We __________________ in the café when they saw us (sit)