By chemically extracting nickel form the ash, they produced 100 pounds of nickel per acre of land at a total cost per pound slightly above that of current mining.
通过化学方法从灰烬中提取镍,他们每英亩土地生产了100磅镍,每磅的总成本略高于目前的采矿成本。
2
The cost we project for saving civilization would amount to less than $200 billion a year, 1/6 of current global military spending.
我们预计每年用于拯救文明的开支合计不到2000亿美元,相当于目前全球军费开支的六分之一。
3
Yet the cost we project for saving civilization would amount to less than $200 billion a year, 1/6 of current global military spending.