一个装满水的玻璃杯的总质量为700g，将一金属块放入水中，待水溢出稳定后，把杯的外部擦干，称得其总质量为1040g，将金属块取出后其剩余的总质量为500g，该金属块的质量为 ____g，为该金属块的密度为 ____kg/m³．（忽略金属块带走的水）

网络是把“双刃剑”，让人欢喜让人忧。阅读图表，回答问题。

材料一：一组让人欢喜的数据。（资料来源：《中国互联网络发展状况统计报告》2016年12月）

材料二：一组让人担忧的场景。

场景一：

    There is a new park near Andy's home. It's fine today. Andy and his family are in the park now. On their left, there is a café. On their right, there is a big lake. There are many flowers and trees around the lake. There's a small hill behind the lake. Near the lake, there are two signs. One says, “Don't swim in the lake!” The other says, “No fishing!” But you can go boating on the lake. There is a beautiful garden in the middle of the park. There are green grass and beautiful flowers in it. There are some small shops between the lake and the garden. The park is so beautiful. Andy and his family like it very much.