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yamahar15
2 năm trước
Lúc 5 giờ hai xe ôtô xuất phát đồng thời từ 2 địa điểm A và B cách nhau 240km và chuyển động ngược chiều nhau. Hai xe gặp nhau lúc 7 giờ. Biết vận tốc xe xuất phát từ A là 15m/s. Chọn trục Ox trùng với AB, gốc toạ độ tại A. a/ Tính vận tốc của xe B. b/ Lập phương trình chuyển động của 2 xe. c/ Xác định toạ độ lúc 2 xe gặp nhau.
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In 79 A.D., the ancient Roman city of Pompeii was destroyed by the eruption of a nearby volcano, Mt. Vesuvius. Although many other cities in history have been victims to eruptions of volcanoes and their deadly gas, lava, and ash, what makes Pompeii especially interesting is what happened years later. In 1748, explorers in the Italian region where Pompeii once stood made an incredible discovery. Buried underneath layers of dirt, the city of Pompeii remained preserved. The original volcanic explosion had happened so quickly that most of the citizens were unable to escape. Their remains and the buildings of the city were still there, preserved, as if the year was still 79 A.D. instead of 1748. Some were frozen as if running from the fiery inferno while others were engaged in normal daily activities. The layers of dust had frozen the day in history. Archeologists would later begin the careful process of excavating the now famous city from the layers of ash. The tragedy of Pompeii is the loss of the city and the approximately two thousand people who died during the eruption. Ironically, the deadly eruption helped preserve Pompeii so that no one will ever forget the name of this ancient Roman civilization. 21. What was the author's purpose in writing this text? A. To inform B. To entertain C. To persuade D. To explain 22. What conclusion can be drawn about the people of Pompeii in the year 79 A.D.? A. Most of the citizens were farmers. B. Women and men were treated equally. C. The citizens of Pompeii were not prepared for the eruption of Mt. Vesuvius. D. The people of Pompeii were unconcerned about living near an active volcano. 23. Using the information from the text, what can you infer an archeologist might do as part of his or her job? A. Study modern events to better understand connections to the past. B. Teach history at the university level. C. Create buildings that have similar architectural designs of the past. D. Excavate and study past civilizations and their artifacts. 24. The underlined word "Some" in the text refers to some ………………. A. citizens B. remains C. buildings D. activities 25. Which of the following can be proven true from the information given in the text? A. Archaeologists believe Pompeii is the greatest historical discovery of its kind. B. The 1748 discovery of Pompeii is considered a significant historical discovery. C. All of the citizens of Pompeii could have survived if they had been given warning. D. Mt. Vesuvius will erupt again within the next ten years.

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