题目

能正确表示下列反应的离子方程式是 A．碳酸氢钙溶液和氢氧化钠溶液混合：HCO3—+OH—==CO32—+H2O B．醋酸钠溶液和盐酸混合：CH3COONa+H+ == CH3COOH + Na+ C．少量金属钠放入冷水中：Na+ 2H2O== Na++2OH—+H2↑ D．硫酸铜溶液和氢氧化钡溶液混合： Cu2+ + SO42— +Ba2+ + 2OH—== Cu（OH）2↓+ BaSO4↓ 答案：D用所给词的适当形式填空。（1）I didn't brush my (tooth) this morning.（2）Sometimes we should feel (luck) to be alive.（3）Life is full of the(expect)（4）I (run)all the way to school yesterday.（5）At the camping site, people sit around the （burn）wood and talk freely.