net freight ton-kilometers

例句：

1. 1.The shipping company charges a flat rate for net freight ton-kilometers.
   这家航运公司对净运费吨公里收取固定费用。
2. 2. To calculate the cost of transportation, we need to consider the net freight ton-kilometers.
   为了计算运输成本，我们需要考虑到净运费吨公里。
3. 3. The shipment was shipped by sea, and the net freight ton-kilometers were calculated based on the cargo weight.
   该货物通过海运发送，净运费吨公里是根据货物重量计算得出的。