rhizagra

例句：

1. 1. The rhizobium bacteria in the soil help plants toabsorb nutrients from the air.
   土壤中的根瘤菌帮助植物从空气中吸收养分。
2. 2. Rhizobium bacteria are essential for thegrowth of many crops.
   根瘤菌对许多农作物的生长至关重要。
3. 3. Researchers have discovered thatcertain rhizobium bacteria can fixnitrogen from the air.
   研究人员发现某些根瘤菌可以从空气中固定氮气。