cho a,b,cthoa man a^2+b^2 +c^2>=3/4

Trong muối ngậm nước Na2CO3.xH2O, Na2CO3 chiếm 37,07% về khối lượng, Xác định giá trị của x.

I.Change the direct sentences into indirect ones: 1. “Turn off the light,” he said to her. à He asked her …………………………… 2. “Close the door, Tom,” she said. à She told Tom ………………………… 3. “Don’t watch the movies too late,” I said to Mary. à I told Marry ………………………………… 4. “Buy a new car,” I advised him. à I told him ………………… 5. “Don’t lend her anything,” he advised us. à He told us ………………………………… 6. “Don’t make too much noise, children,” he said. à He told the children……………… 7. “Please help Nam to study well in English.” The teacher said to Nga.The teacher told Nga ……………………… 8. “wait for me outside the class, please.”Lan said to Minh. à Lan told Minh ………………………… 9. “Don’t touch it!” He told the child. à He told the child … 10. His wife said, “Write to me as often as you can.” à His wife told him …………………………… 11.She said, “Don’t go near the water, children.” à She told the children………………………… 12. “Could you help me, please?” he said to her. à He asked her ………………………………… 13. “Will you be here tomorrow?” she asked. à She asked him …………………… 14. “Will you read this carefully?” he said to me. à He asked me ………………………………… 15 “Could you meet me next week?” Tim asked me. à Tim asked me ………………………… 16 “ Can you give me some small money, mom ?”.Minh asked his mom …………………

Câu 1: Cho tam giác ABC vuông tại A có AB 9 cm,BC 15 cm.AH = = là đường cao (H thuộc cạnh BC ). Tính BH,CH,AC và AH.

IV .Put the verbs in the correct verb: 1. Hoa (have) __________lot of friends in Hue. 2. She (be) _____________unhappy now. She (miss) ______________ her parents in Hue. 3. Hoa (talk)_______________to Ms. Lien at the moment. 4. She (be) ______________14 on her next birthday. 5. Hoa’s old school (be)___________ small. It (not have)__________________many students. 6. I (walk) ___________to school every day, but today I (ride)_______________my bike to school. 7. We (not, go)_________________ to class on Sunday. 8. My best friend (come)________________here soon. 9. (you, be)_____________________ free next Sunday? – No. I (do) _____________my homework. 10. Phong (be) _____________on the phone now. He (talk) ________________to Tam. 11. Listen! Jane (play)_________________the piano. 12. I’d like (visit)____________________Japan some day. 13. We (visit) _____________Huong Pagoda next week. 14. I (come)_______________back tomorrow. 15. Mike (not, come) ______________to our party tonight. 16. Lan (invite)________________ her friends to her next bithday party on Sunday.. 17. Jim (often, watch) _____________television at night. 18. Who (Miss Hoa, talk)______________________to in the school yard at the moment? 19. Would you like (see) ______________ a movie? 20. Her class (have)______________forty students. 21. Lan (not, be)____________in her room at the moment. She (work) _____________in the garden. 22. They (not, go) ______________camping next week. They (visit)________________the museum. 23. This (be) ________my sister. She (be)__________________25 on her next birthday.

Many people love boats. Going out on the water on a warm summer day is a lot of fun. (42) _______ ,different people like different kinds of boats. Two of the most popular kinds of boat are sailboats and speedboats. Sailboats use the (43) _______to give them power. They only have small engines. In contrast, speedboats have large engines and go very fast. Furthermore, speedboats are usually not as (44) _______ as sailboats. Speedboats are small so that they can go fast. Sailboats, on the other hand, are big so that they are more comfortable. ( 45) _______, sailboats can travel into the ocean, but this would be very dangerous in a speedboat. You can only use speedboats on rivers or lakes.

IV. Complete the sentences with the correct form (to-infinitive or -ing form) of the verbs in the box. Some verbs can be followed by either a to-infinitive or an -ing form. 1. My brother loves _____________ live football on TV. 2. Do people in your country like _____________ abroad on vacation? 3. Riding a bike is Lan’s pleasure, but she detests _____________ in the rain. 4. I don’t mind _____________ at home to look after the children. 5. As a child, he hated _____________ books, but now he finds it enjoyable. 6. Minh is in good shape. He enjoys _____________ sport and exercise. 7. She doesn’t like _____________ up early in the morning, especially at the weekend. 8. Emily dislikes _____________ crafts, but she enjoys origami. 9. I fancy _____________ out tonight because I’m too tired to cook. 10. Nancy adores _____________ with her best friend Helen. V. Complete the sentences with the to-infinitive or -ing form of the verbs in brackets. 1. I have enjoyed ___________ (meet) you. Hope ___________ (see) you again soon. 2. My father is not keen on coffee. He prefers ___________ (drink) tea. 3. I am a little busy. Would you mind ___________ (wait) a little longer? 4. Mobile games are great, but I don’t like ___________ (play) them for too long. 5. If I can choose, I prefer ___________ (stay) at home to ___________ (play) sport. 6. Tonight I’d like ___________ (go) out, but I have to do my homework. 7. Sue loves ___________ (make) origami. She can fold some animals, birds and flowers. 8. I detested ___________ (spend) two hours every day travelling to work and back. 9. He started ___________ (surf) the net hours ago. Has he stopped ___________ (surf) yet? 10. I tried hard ___________ (concentrate), but my mind kept ___________ (wander).

A. PHONETICS I. Choose the word that has the underlined part pronounced differently from the others. 1. A. neighbor B. cough C. although D. drought 2. A. entertain B. rain C. air D. strain 3. A. try B. facility C. typhoon D. supply 4. A. supermarket B. ruler C. pollution D. urban 5. A. nature B. migrant C. facility D. away 6. A. traffic B. relative C. tragedy D. jam 7. A. apartment B. offer C. prefer D. another 8. A. nature B. pressure C. urban D. supply 9. A. create B. peaceful C. increase D. easily 10. A. accessible B. pressure C. illness D. success

Điền đơn thức thích hợp vào chỗ trống:-7 ích ngũ 2 y z 3-...........=-11 ích ngũ 2 y z 3 đó là đơn thức

Một xe đạp đi trên đoạn đường thẳng AB. Trên 1/3 đoạn đường đầu xe với vận tốc v1 = 15km/h. Trên 1/3 đoạn đường sau xe với vận tốc v2 = 10km/h. Trên 1/3 đoạn đường cuối cùng xe với vận tốc v3 = 8 km/h. Tínhvận tốc trung bình của xe đạp trên cả đoạn đường AB.