be important 之后何时用to 何时用for?

问题描述:

be important 之后何时用to 何时用for?
初三课本上有water is important for China.和 Water is important to invironment.两句,有何区别?

这里for/ to 都是"对于".
for sb. "对某人来说",它的含义更客观:水对于中国来说很重要
to sb. "对某人来说"它的含义更主观 :水对于环境很重要