submain canal

例句：

1. 1. The submain canal is a crucial part of the water system.
   次要运河是水系统的重要组成部分。
2. 2. The construction of this submain canal will greatly improve our transportation network.
   建造这条次要运河将大大改善我们的交通网络。
3. 3. Due to its submain canal, the area around the river has been experiencing more frequent flooding.
   由于其次要运河的存在，该地区的河流周围经常发生洪水。