oxygen-free flux

例句：

1. 1.The oxygen-free flux in the river has been reduced significantly.
   河流中的无氧流已经显著减少。
2. 2. The oxygen-free flux in the river has been reduced significantly.
   河流中的无氧流已经显著减少。
3. 3.The oxygen-free flux in the river has been reduced significantly.
   河流中的无氧流已经显著减少。