the end of a leaf

例句：

1. 1. The leaves are turning yellow as the season changes.
   随着季节的变化，叶子正在变黄。
2. 2. The scientist carefully examined the petiole of the plant to determine its health.
   科学家仔细检查了植物的叶柄，以确定它的健康状况。
3. 3. The leafy greenery provides a refreshing change from the concrete jungle.
   郁郁葱葱的绿色为混凝土丛林带来了一种清新的变化。