问题
选择题
2A + 3B==C +3D 中A和C的相对分子质量比为3:38，D的相对分子质量为2 。已知一定量的A和B恰好完全反应，生成34.2gC和0.6gD，则B的相对分子质量为 [ ]
A．36.5
B．63
C．98
D．294
答案
答案：C
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2A + 3B==C +3D 中A和C的相对分子质量比为3:38，D的相对分子质量为2 。已知一定量的A和B恰好完全反应，生成34.2gC和0.6gD，则B的相对分子质量为 [ ]
A．36.5
B．63
C．98
D．294
答案：C
| 完形填空。 This year is World Conservation (保护) Year. The United Nations wanted everyone to know that the world is 1 . They hoped that the governments would act quickly in order to conserve 2 . Here is one example of the problems. 3 there were 1,300 different plants, trees and flowers in Holland but now only 866 remain. 4 have been destroyed by modern man and his technology. We are changing the earth, the air and water, and everything that 5 and lives. We can't live without these things. If we continue to do things 6 this, we shall destroy ourselves. What 7 in the future? Perhaps it is more important to ask "What must we do now?" The people who will be living in the world of tomorrow 8 the young of today. A lot of them know that conservation is necessary. Many are helping to 9 . They plant trees, build bridges across rivers in forests and so on. In a small town in the United States a large group of girls cleaned the banks of 11 kilometers of their rivers. Young people may hear about conservation through 10 called "No one's going to change our world." It was made by the Beatles, Cliff Richard and other singers. The money from it will help to conserve wild animals. | ||||
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