龙门起重机

例句：

1. 1. The crane is used for lifting heavy loads across the river.
   这个起重机用来在河上吊起重物。
2. 2. The crane operator carefully maneuvers the heavy load onto the dock.
   起重机操作员小心翼翼地将重物移到码头上。
3. 3. The crane is essential for moving heavy equipment and materials across large distances.
   起重机对于搬运重型设备和材料跨越大距离至关重要。