An emergencyextension system extends the gear mechanically if hydraulic or electrical power is lost.
如果液压系统或者电源出现故障，应急放出系统会靠重力机械地放出起落架。
2
The extension provides an opportunity to improve the relationship between the school complex and the public space in the street currently a blank wall of the emergency shelter.
扩建给学校和城市公共空间提供了改善关系的契机——有一个可供紧急避难的场所。
3
Developing an efficient Railway Emergency Communication System was important to reduce the loss of accident, prevent the extension from the disaster.