km.
abbr. 公里（kilometer）；千兆（kilomega）
例句
For those uninitiated in scientific ocean drilling, the previous record was a little over 4 km.
可以告诉没有海洋科学钻探知识的人，先前的纪录是四公里过一点儿。
《柯林斯英汉双解大词典》
The trip is about 36,000 km.
行程约3.6万公里。
It was finished in 2019, helping shorten the 18-km distance over the mountain to 5.7 km.
隧道于2019年竣工，将18公里的路程缩短至5.7公里。
