Dall tube

例句：

1. 1. The engineer designed a new dam to control the flow of water.
   工程师设计了一座新的大坝来控制水流。
2. 2.The scientist used a dal tube to collect samples from the river.
   科学家使用一根管子从河里收集样本。
3. 3.The construction workers were using a dal tube to transport materials.
   建筑工人正在使用一根管子运输材料。