translation.en: He wanted to estimate N, the number of communicative civilizations out there in our galaxy, and he included in there the rate of star formation, the rate of planets, but crucially, intelligence.
translation.zh: 他想估计N， 我们星系中有沟通文明的星球的数量。 他包括了星球成型的比率， 行星的比率，以及最关键的，智慧。