Na₂CO₃溶液（NaHCO₃）：试剂____，离子方程式____．

唐朝时的水路交通线发达，南方的出发地是(    )

    Do you know the boy in the picture? He is Yi Yangqianxi. His English name is Jackson. Yi is 15 years old. He is a student in a school in Beijing. And he is also a boy in the group (组合) TFBOYS.

    TFBOYS has three boys — Wang Yuan, Wang Junkai and Yi Yangqianxi. All of them are tall and have good looks. They are good at dancing and singing.

    Wang Yuan and Wang Junkai are Yi's friends. And Yi has another (另一个) friend. He is a toy bear. He lives in Yi's schoolbag. Yi goes to school with him every day. He talks and plays with him. “He can't talk, but he can listen to me. He is very nice. I like him very much,” Yi says. “I don't want to be away from him.”