题目

I’m afraid we can’t finish the task as scheduled. Can we ask the boss to have the deadline ? A.expanded                 B.confirmed                C.extended                 D.stretched 答案：C下列离子方程式书写正确的是 A. FeSO4酸性溶液暴露在空气中：4Fe2＋＋O2＋4H＋=4Fe3＋＋2H2O B. 过氧化钠固体与水反应：2O22-+2H2O=4OH-+O2↑ C. NH4HCO3溶液与过量的NaOH溶液反应：NH4++OH-=NH3↑+H2O D. 用氨水检验氯化钠溶液中混有氯化铝杂质：Al3++4NH3·H2O=AlO2-+4NH4++2H2O