题目

Life has changed in Mexico City．Streets normally filled with people are empty．One of the most popular professional soccer teams recently played a game in an empty stadium that can seat more than100,000 people．It's swine （猪）flu that has made life in Mexico City grind to a halt （慢慢停了下来）． Seemingly out of nowhere, swine flu has caused confirmed deaths in 12 countries as of April 30．It has sent a wave of alarm around the world．Governments are trying to find ways to prevent further out-breaks．The World Health Organization has raised its swine flu global threat le下列反应的离子方程式书写正确的是(　　)①硫酸铜溶液与氢氧化钡溶液反应：Ba2＋＋SO42—=BaSO4↓②将金属钠加入水中：2Na＋2H2O=2Na＋＋2OH－＋H2↑③石灰石溶于稀醋酸：CaCO3＋2CH3COOH=2CH3COO－＋Ca2＋＋CO2↑＋H2O④氯气与水反应：Cl2＋H2O=H＋＋Cl－＋HClO⑤小苏打溶液中加入少量石灰水：Ca2＋＋2OH－＋2HCO3—=CaCO3↓＋CO32—＋2H2O⑥次氯酸钙溶液中通入过量CO2：Ca2＋＋2ClO－＋CO2＋H2O=CaCO3↓＋2HClO⑦钠与硫酸铜溶液反应：Cu2＋＋2Na=Cu＋2Na＋⑧纯碱溶液中滴加少量盐酸：CO32—＋H＋=HCO3—A．①②⑤ B．②③④⑤⑧ C．④⑤⑥⑦ D．②③⑧