Các câu ví dụ cho từ gravel

1. The global demand for sand and gravel, which is widely used in construction, is about 50 billion tons per year, according to a report released by the United States.

2. A spokesman for Indonesia's National Disaster Mitigation agency, said via a text message that there had been a "phreatic eruption" late on Tuesday with black smoke reaching 700 metres (2,300 ft), followed by falling ash, gravel and sand.