题干

常见的五种盐A、B、C、D、E,它们的阳离子可能是Na+、NH4+、Cu2+、Ba2+、Al3+、Ag+、Fe3+,阴离子可能是Cl-、NO3、SO42、CO32.已知:

①五种盐均溶于水,水溶液均为无色.

②D的焰色反应呈黄色.

③A的溶液呈中性,B、C、E的溶液呈酸性,D的溶液呈碱性.

④若在这五种盐的溶液中分别加入Ba(NO32溶液,只有A、C的溶液不产生沉淀.

⑤若在这五种盐的溶液中,分别加入氨水,E和C的溶液中生成沉淀,继续加氨水,C中沉淀消失.

⑥把A的溶液分别加入到B、C、E的溶液中,均能生成不溶于稀硝酸的沉淀.

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    Garbage(垃圾) Island

    You can't see it from the air. It's almost impossible to see from a ship. But somewhere in the North Pacific is a huge island of garbage, just below the water surface.

    What is the island made of?

    The garbage island is not an island, but a collection of millions of plastic and other objects. The water movements of Pacific Ocean bring the objects together and cause them to go around in a big circle.

    Charles Moore found it in 1997 and named it “the Great Pacific Garbage Patch” .

    Where does all the plastic come from?

    Much of the garbage comes from everyday objects, such as shopping bags and water bottles. Some of these objects finally reach the ocean. Garbage from the western coast of North America takes about six years to reach it. Objects from East Asia take about a year. Other garbage comes from ships passing through the area.

    Is the Garbage Patch dangerous?

    The larger pieces of garbage are a problem for wildlife. For example, sea turtles(海龟)and seabirds often think the plastic is their food. They eat the plastic and die.

    In addition, the plastic stops sunlight from reaching deeper water. Without sunlight, very small sea animals die. Then, there is less food for larger fish to eat.

    What can we do to help stop it?

    Cleaning up the island isn't easy. But we can make people realize the problem. One environmentalist(环保主义者), David de Rothschild, is sailing around the world in boat made of plastic bottles to teach people about the problem of garbage in the sea.

    Another idea is that we can recycle the plastic garbage. Environmental engineer Cesar Harada is building a robot that collects pieces of plastic. Harada hopes to use his robot in the Pacific. Harada also has a website for reporting environmental problems. He says, “I hope everybody can become an environmental activist.”