...备，当一个或几个UPS单元故障时，其余的UPS可以完全地承载全部负载； 设备和部件的性能（performance of system and components） 主电源（primary power）：在正常情况下，可以持续供电的电源，一般由电力公司供电，但有是由用户自己发电； 备用电源（standby...
Some of the reasons cited are shortages of key components in part due to the Japanese quake and unstable performanceof Android Honeycomb operating system, which Google specifically developed for tablets.