“灰质”造句
脊髓
灰质软化病主要侵害肥育猪群.
Poliomyelomalacia affected primarily fattening stock.
每个珊瑚虫有
灰质的骨骼.
Each animal has a chalky skeleton.
自然堆积的
灰质鲕粒砂具有40%的孔隙度,因为其颗粒其本上都是球状的.
Oolite lime sand packs naturally with 40 % porosity because the particles are essentially spheroids.