It is so convinient to use them when a fire happens. In Europe you can't find so mass installations in the street, maybe because the emergency offices have movableequipment.
在欧洲，你在街头看不到这么多的消防设施建在街头，或许是因为突发事件处理部门都用移动的设备。
3
The loads a structure is subjected to are divided into dead loads, which include the weights of parts of the structure, and live loads, which are due to the weights of people, movableequipment, etc.