sand-gravel aggregate

例句：

1. 1. The construction of the highway required a large amount of sand-gravel aggregate.
   修建高速公路需要大量的砂砾集料。
2. 2.The engineer carefully mixed different types of sand-gravel aggregate to ensure the quality of the road surface.
   工程师仔细混合不同种类的砂砾集料，以确保道路表面的质量。
3. 3. Due to the high demand for sand-gravel aggregate, the price has been on the rise recently.
   由于对砂砾集料的高需求，最近价格一直在上涨。