*Đáp án:
Cặp chất để điều chế khí H2 trong phòng thí nghiệm là * 1 điểm
A: Zn và CO
B: Zn và KMnO4
C: Zn và HCl
D: Zn và KClO3.
*Vì:
Zn + HCl → Zn$Cl_{2}$ + $H_{2}$ ↑
#NOCOPY
Bạn tham khảo nha!
Đáp án: `C`
`->` `Zn + HCl -> ZnCl_2 + H_2 ↑`
ai giúp mình với ạ~~~~ cảm ơn nhiều nhiều
Read the passage about UNESCO and circle the correct option (A, B, C, or D) to answer each of the given questions. (1 point) In 1959, the government of Egypt was working on a plan to build a dam on the River Nile. It was called the Aswan Dam, and it was intended to generate electricity and allow the river water to be used for agriculture. There was one big problem with the plan, though. The dam would flood a nearby valley that contained ancient Egyptian treasures, including two enormous stone temples. It can be difficult for governments to choose culture and history over economics. However, if countries always made decisions like this, the majority of the world's ancient sites would end up being destroyed. Luckily, UNESCO stepped in. They formed a committee that tried to convince Egypt to protect its ancient treasures. With support from many countries, they were finally successful. The huge temples were carefully removed from their original site and moved to a safe location so that the dam could be built. After their success in saving the temples in Egypt, UNESCO went on to save more sites around the world. They protected lagoons in Venice, ruins in Pakistan, and temples in Indonesia. With industrialisation changing the world rapidly, there were many sites that needed to be saved. Eventually, UNESCO formed the World Heritage Organisation to protect important natural and historic sites wherever it was necessary. By now, the World Heritage Organisation has protected hundreds of sites ranging from beautiful natural islands to buildings in large cities and ancient ruins. If you're able to visit any of the many protected sites, you'll agree it was worth it. 6. What is the best title for the passage? A. UNESCO B. UNESCO to succeed C. UNESCO to develop D. UNESCO to rescue 7. The word “this” in paragraph 2 refers to ____________. A. culture B. decision C. country D. economics 8. What is meant by the first sentence of the second paragraph? A. Most governments prefer to sell their treasures. B. Money sometimes seems more important than all other things. C. Governments are never able to consider two things at once. D. Governments usually don't know anything about their culture. 9. Why did UNESCO get involved in Egypt? A. Egypt was planning to build a dam that would harm ancient temples. B. Egypt was planning to build a valley for agriculture and electricity. C. Egypt was planning to create a dam right on top of an ancient temple. D. When the dam flooded a valley, several treasures were discovered. 10. Why is the World Heritage Organisation more important now than it would have been 200 years ago? A. Countries didn't cooperate in the past. B. Cities were smaller back then. C. There were not as many interesting sites 200 years ago. D. Modern business and production are changing the world.
vì sao cùng hoàn cảnh như nhật bản mà việt nam không thực hiện được cải cách duy tân ,liên hệ với công cuộc đổi mới nước ta hiện nay
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