中游

The paper highlighted the existing situation of soil gleying and swamping,thecause and harm of soil waterlogging.

讨论了游地区土壤潜育化沼泽化现状,土壤渍害的原因及其危害,并总结提出了一些改良措施。

It is a tiny joyrider from the rubble stream surrounding the solar system that broke free and orbits the sun in a tilted, elongated orbit.

它是从围绕太阳系而又自由动的一堆剩余物游走出来的一颗星。它体积微小，以倾斜、细的轨道围着太阳运转。