translation.en: In the tropics, raindrops are not formed from ice crystals, which is the case in the temperate zones, you need the trees with [unclear], chemicals that come out of the leaves of the trees that initiate the raindrops.
translation.zh: 在热带地区，雨水不是由冰晶形成的， 好比温带地区的情况， 你需要化学成分从树叶中产出 这才会开始产生降雨。