The most common reason is when a shoe breaks off and its connectinglead to the electrical equipment on the train has to be secured safely.
最常见便是一个集电靴突然中止，连接火车电力设备的导线需要被安全保护起来的情况。
2
Connecting the PPS system to any number of suppliers, each with its own protocol and data format, can lead to a significant amount of code that must be developed.
The UTC? range is especially designed for connecting pipes that are made from a variety of different materials, such as polyethylene, galvanized steel, PVC, copper, ABS, lead and stainless steel.