gravel

砂跞；砂砾层；结石英释nnsmall stones, used to make a surface for paths, roads etc

1 gravel layer,砾石层；疏水石

2 sandy gravel,砂砾石，砂质砾石

3 gravel pack,砾石过滤层

4 gravel road,碎石路

5 sand gravel,砂砾石

1 a gravel path.石子小道