阅读下列四篇短文，从每小题后所给的A,B,C或D四个选项中，选出最佳选项。
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 heating 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.
