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sangtrangvi
2 năm trước
19. Một người đứng giữa một phòng kín nói to lên, muốn nghe thấy tiếng vang thì khoảng cách giữa người và các bức tường phải tối thiểu là bao nhiêu mét?( vận tốc truyền âm trong không khí 340m/s)
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Các câu hỏi liên quan

I. One of the four underlined parts each sentence is not correct in Standard English. 1. If Lucia had been here now, she would find out the truth about her uncle’s accident. .............................. 2. If had I known you were in financial difficulty, I would have helped you. ........................................ 3. If a student takes a course on Computer Science, it will take him four years doing the course. ................. 4. If she had finished the work, she can go home. ........................................ 5. Unless there had been the heavy storm, the climbers will not have died. ........................................ 6. If I had spoken more confident at the interview, they would have offered me the job. .............................. II. Complete each sentences with the correct form of the verb in brackets (3 points) 1. Phuc enjoyed (chat) .................................................... on the phone with her friends. 2. He has decided (go) ........................................................... to work in a school in a quite remote area. 3. We’ll need (call) .....................................him more often. 4. She dislikes (communicate) .....................................through message board or online meetings. 5. I tried (explain) ......................................it to him, but he didn’t understand 7. Which TV programme (you, watch) ........................................ at 9 p.m. tomorrow? 8. They didn’t mind (work) ....................................late to complete the task. 9. He intends (stay) ........................................ there for at least three years. 10. We plan (have) .................................................a picnic this Sunday. Would you like to join us? 11. I’ll need (take) ....................................the bus to Nguyen Du Street. 12. You should avoid (use) ................................... too much shorthand in formal online communication. 13. I hope you (not work) ........................................ when I arrive at 8 p.m. today III. Change the following sentences from active into passive form. 1. Somebody has taken my briefcase. 2. The teacher returned our written work to us. 3. She had finished her report by soon. 4. The mad dog bit the little boy. 5. The police have arrested five suspects. 6. The doctor ordered him to take a long rest. 7. I am lightening a paper. 8. A group of students have met their friends at the rail way station. 9. They didn’t allow Tom to take these books home. 10. The teacher won’t correct exercises tomorrow. 11. Marry has operated Tom since 10 o’clock. 12.This is the second time they have written a letter to us. 13. Mr. Smith has taught us French for two year. 14. They didn’t look after the children properly. 15. Nobody swept this street last week. 16. People drink a great deal of tea in England.

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