起重三角架

例句：

1. 1. This crane is used for lifting heavy loads.
   这台起重机用于吊装重物。
2. 2. The engineer needs to check the stability of the crane before operation.
   工程师需要检查起重机的稳定性，以确保操作安全。
3. 3. The crane operator must follow safety procedures while operating the machine.
   起重机操作员在操作机器时必须遵循安全程序。