Leaves are not distributed ________on a plant stem, but are arranged in a very precise way that assures them the maximum light.
句意：树叶并不是随意地分布在树干上，而是以一种非常精确的方式排列，以确保它们获得的光照最多。randomly随便地，任意地。densely浓密地。linearly成直线地。