白铜(Cu、Ni合金)因为光泽好、耐腐蚀、容易加工等优点，常代替银做饰品。下图所示是某实验室分离废弃白铜饰品成分的流程(部分反应产物在图中已略去，Ni在化合物中显+2价，溶液B中只有一种溶质)。

分析该流程，回答下列问题：

在第一个五年计划时期，各行各业的劳动者满怀激情地投入到社会主义建设中去，进行技术革新。先后八次改进工具，发明了“万能工具胎”是(     )

中国历代封建政府大都采取了重农抑商的政策，其原因不包括

图甲和图乙分别表示北半球某滨海地区海陆环流和海陆气温变化特征。回答下面小题。

    Many people like spring, because they can go out and do many kinds of activities. We made a survey about the activities that people like to do in spring. Here are the results.
Scott：
    In spring, I often visit my uncle and I like fishing with him. I also like boating and enjoy the beach. Last spring my uncle and I went boating. The dolphins came so close to us. It was very amazing. I hope that I can go there again soon.
Linda:
    My favorite spring activity is gardening (园艺). I think it is relaxing to work in the garden. I grow many flowers in my garden every year. They are so beautiful.
Nancy：
    I love spring. I love going to the beach and spending a whole day there. It is so relaxing to lie on the beach. I also like surfing in the sea.
James：
    I am twelve years old. My favorite spring activity is swimming. I started to learn swimming when I was seven years old. I always have a good time with my friends in the river.