题干

为探究原电池的形成条件和反应原理,某同学设计了如下实验并记录了现象:
①向一定浓度的稀硫酸中插入锌片,看到有气泡生成;
②向上述稀硫酸中插入铜片,没有看到有气泡生成;
③将锌片与铜片上端接触并捏住,一起插入稀硫酸中,看到铜片上有气泡生成,且生成气泡的速率比实验①中快;
④在锌片和铜片中间接上电流计,再将锌片和铜片插入稀硫酸中,发现电流计指针偏转。下列关于以上实验设计及现象的分析,不正确的是(    )

A:实验①、②说明锌能与稀硫酸反应而铜不能

B:实验③说明发生原电池反应时会加快化学反应速率

C:实验③说明在该条件下铜可以与稀硫酸反应生成氢气

D:实验④说明化学能可以转化为电能

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C

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    We already know the fastest, least expensive way to slow climate change: Use less energy. With a little effort, and not much money, most of us could reduce our energy diets by 25 percent or more—doing the Earth a favor while also helping our wallets.

    Not long ago, my wife, PJ, and I tried a new diet—not to lose a little weight but to answer an annoying question about climate change. Scientists have reported recently that the world is bending up even faster than predicted only a few years ago, and that the consequences could be severe if we don't keep reducing emissions(排放) of carbon dioxide (CO2 ) and other greenhouse gases that are trapping heat in our atmosphere.

    We decided to try an experiment. For one month we recorded our personal emissions of CO2. We wanted to see how much we could cut back, so we went on a strict diet. The average US household(家庭) produces about 150 pounds of CO2  a day by doing common-place things like turning on air-conditioning or driving cars. That's more than twice the European average and almost five times the global average, mostly because Americans drive more and have bigger houses. But how much should we try to reduce?

    For an answer, I checked with Tim Flannery, author of The Weather Makers: How Man is Changing the Climate and What it Means for Life on Earth. In his book, he had challenged readers to make deep cuts in personal emissions to keep the world from reaching extremely important tipping points, such as the melting(融化) of the ice sheets in Greenland or West Antarctica. "To stay below that point, we need to reduce CO2  emissions by 80 percent," he said.

    Good advice, I thought. I'd opened our bedroom windows to let in the wind. We'd gotten so used to keeping our air-conditioning going around the clock. I'd almost forgotten the windows even opened. We should not let this happen again. It's time for us to change our habits if necessary.