distance sink tube

例句：

1. 1. The distance between the two citiesis about 500 kilometers.
   两座城市之间的距离大约是500公里。
2. 2.The distance between the two countries is stilla matter of debate.
   两国之间的距离仍然是个争论的话题。
3. 3. The distance between the stars inthe sky is so vast that it seemslike they are far apart.
   天空中的星星之间的距离如此遥远，看起来它们似乎相隔甚远。