sterile tobramycin

例句：

1. 1. The soil is sterile, making it difficult for plants to grow.
   土壤是无性的，使得植物难以生长。
2. 2. The couple has been trying for yearsto have a child, but they arestill sterile.
   这对夫妇已经尝试了多年想要孩子，但他们仍然无性。
3. 3.The farmer was sterile because of hisexposure to radiation.
   这位农民由于受到辐射的影响而变得无性。