The only thing predictable about life is its unpredictability. 生活唯一可预知的便是它的不可预知性。
In the temperate zone in spring, temperatures fluctuate greatly from day to day, but day length increases steadily by a predictable amount. 春天的温带地区,气温每天都变化不定,但是日照长度却以一个可预知的数量稳步增加。