题目: Helen always helps her mother even though going to school _____ most of her day.[ ]A. takes upB. makes up C. saves upD. put up 答案: 答案:A
题型:选择题 下列离子方程式书写正确的是:( )A.金属钠投入到水中 Na + 2H2O ="=" Na+ + 2OH— + H2↑B.CaCO3与盐酸反应 CO32— + 2H+ ="=" CO2↑ + H2OC.制备Fe (OH)3 胶体:Fe3+ + 3H2OFe(OH)3↓ + 3H+D.碳酸氢钠溶液与盐酸反应:HCO3— + H+ ="=" CO2↑ + H2O 查看答案