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阅读理解 People typically wash their hands seventimes a day in the United States, but they do it at a far higher temperature thanis necessary to kill germs, a new study says. The energy waste is equivalent tothe fuel use of a small country. Amanda R. Carrico, a research assistant professorat the Vanderbilt Institute for Energy and Environment in Tennessee, told NationalGeographic that hand washing is often “a case where people act in ways that theythink are in their best interest, but they in fact have inaccurate beliefs or outdatedperceptions.” Carrico said, “It's certainly true tha质量为m的小球，从离桌面以上高为H的地方以初速度v0竖直向上抛出，桌面离地面高为h，设桌面处物体重力势能为零，空气阻力不计，那么，小球落地时的机械能为 A．mgh＋ B．mg（H +h） C．mg(H+h) ＋ D．mgH＋