what precious resource do Americans value and save ?

the power in their heart to struggle to be the best

American dream,I think.
Because Aerican are pround of their fair.
The American pay great attention to their chances.we can try hard to reach our ambitions.

in my opinion,slef dependence may be the first one ,it's because a lot of Amaricans don't have all their money left to their children,on the contrary,they send it to the pablic,to the poor,and so on. the second is the pursuit of freedom,which help them to fight with the english and build up this new United nation that is full of vitality .

美国人珍惜和保护的珍贵资源都有哪些？