translation.en: I recall the very moment one day when I was searching for a pair of metals that would meet the constraints of earth abundance, different, opposite density and high mutual reactivity.
translation.zh: 我记得某天某刻 当我在寻找一些能够 满足我的条件的金属， 那些在地球上大量存贮 不同的相对密度 与高互反应性的金属的时候。