boom excavator

• 臂式挖土机,吊杆挖土机

boom excavator的用法和样例：

例句

1. In an earthwork,the conveyance is like a consumer due to waiting for necessary loading capacity,and then an excavator is the same as a service system.
   在土方开挖工程中，汽车要等待挖土机挖土，汽车就是顾客，挖土机就是服务机构，二者形成一个排队系统。