公里的

例句：

1. 1. The distance between the two cities is about 30 kilometers.
   两座城市之间的距离大约是30公里。
2. 2. We need to travel at least 5 kilometers to reach the next town.
   我们需要至少走5公里才能到达下一个城镇。
3. 3. The marathon race covers a total of 42 kilometers.
   马拉松赛跑全程42公里。