node of Keith-Flack

例句：

1. 1. The tree has many branches and leaves.
   这棵树有很多分支和叶子。
2. 2. The scientist used a microscope to observe the structure of the cell.
   科学家使用显微镜观察细胞的结构。
3. 3. The city is divided into several districts by major roads.
   这个城市通过主要道路分成几个区域。