| 1. | Sand and gravel may form bars within the channel . 沙和砾石可以在沟槽内形成沙洲。 |
| 2. | Gravel is much used for road-making . 砾石常用来筑路。 |
| 3. | Gravel banks along rivers are always light or white . 河流的砾石滩始终为浅色或白色。 |
| 4. | They may form concentrated pockets in gravels . 它们可能在砾石堆积物中形成富集的矿囊。 |
| 5. | More gravel is needed to fill the hollow in the drive . 需要更多的砾石来填平车道上的坑洼。 |
| 6. | Sand is finer than gravel . 沙子比碎石细。 |
| 7. | A layer of coarse gravel is often placed around the drain tile . 常常在排水瓦管周围铺一层粗石砾。 |
| 8. | He went down the broad gravel path towards the building . 他顺着石子铺的宽甬路,朝着那座大楼走去。 |
| 9. | Suction devices are inadequate in gravels or very porous soils . 吸水装置对砂砾或非常疏松的土壤是不适用的。 |
| 10. | The channel is filled with noncompactible sand, or with sand and gravel . 水道内由不可压实的砂或砂砾物质充填。 |