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问题 选择题

证明某溶液只含有Fe2＋而不含有Fe3＋的实验方法是 (   )

A．先滴加氯水，再滴加KSCN溶液后显红

B．只需滴加KSCN溶液

C．先滴加KSCN溶液，不显红色，再滴加氯水后显红色

D．加Na2O2固体后观察沉淀颜色的变化

答案

答案：C

题目分析：证明不含Fe3+可加KSCN溶液，溶液不显红色，再证明含有Fe2+，只需加入合适的氧化剂（如氯水），溶液变为血红色。若向溶液中加过氧化钠固体后最终产生红褐色沉淀，不能证明只有Fe2+而没有Fe3+。

点评：检验Fe2+离子的方法是先加KSCN溶液无现象，再加少量氯水，溶液变为血红色。

单项选择题

Industrial pollution is not only a problem for the countries of Europe and North America but also an extremely serious problem in some developing countries. For these countries, economic growth is a very important aim. They want to introduce industries, and so they put few controls on the industries which cause pollution.
Cubatao, an industrial town of 85 000 people in Brazil, is an example of the connection between industrial development and pollution. In 1954, Cubatao had no industry. Today it has more than twenty large factories, which produce many pollutants. The people of the town are suffering from the poisonous matter in their environment and the bad effects can be clearly seen. Birth shortcomings are extremely common. Among children and adults, lung problems are sometimes twelve times more common in Cubatao than in other places.
It is true that Brazil, like many other countries, has laws against pollution, but these laws are not enforced strictly enough. It is cheaper for companies to take no notice of the laws and pay the fines than to buy the expensive equipment that will reduce the pollution. It is clear, therefore, that economic growth is more important to the government than to the health of the workers. However, the responsibility does not completely lie with the Brazilian government. The example of Cubatao shows that international companies are not acting in a responsible way either. A number of the factories in the town are owned by large companies from France, Italy, and the US. They are doing things in Brazil that they would not be able to do at home. If they caused the same amount of pollution at home, they would be severely punished or even put out of business.

Why don’t developing countries have strict pollution controls

A. The new industries they want to introduce do not cause much pollution.
B. Pollution is not a serious problem for developing countries.
C. They don’t realize the balance of nature will be destroyed by some pollutants.
D. If they put stricter controls on industry, fewer companies would build new plants in developing countries.
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多项选择题

企业向银行借入9个月的借款80000元，存入银行，不正确的会计分录为（）。

A．借：短期借款 80000 贷：银行存款80000

B．借：银行存款80000 贷：长期借款80000

C．借：银行存款80000 贷：短期借款80000

D．借：银行存款80000 贷：应付账款80000
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