gantry crane with level luffing crane

例句：

1. 1. Thegantry crane is used tolift heavy loads from the ground.
   龙门起重机用于从地面吊起重物。
2. 2. Thetower crane is a versatile piece ofmachinery that can be used for various tasks.
   塔式起重机是一种多功能的机器，可以用于各种任务。
3. 3. The gantry crane has been a crucial tool in constructionprojects for decades.
   龙门起重机几十年来一直是建筑项目中的关键工具。