【多选题】关于UPS电源,下列说法哪一些正确
A.
当市电意外停电时,UPS能自动立即接替市电给计算机等电子设备短时供电
C.
UPS的蓄电池组一般采用免维护密封型铅酸蓄电池
E.
UPS一般具有普通交流稳压电源的稳定电压、滤除噪波的作用,但是肯定不具备稳频的作用
【单选题】一品红为大戟属的观赏植物。其最引人注目的是( )。
【多选题】下列关于站用交流电源系统自动切换装置说法正确的是()。
A.
站用电切换及自动转换开关、备用电源自投装置动作后,应检查备自投装置的工作位置、站用电的切换情况是否正常,详细检查直流系统,UPS系统,主变压器(高抗)冷却系统运行正常
B.
站用电正常工作电源恢复后,备用电源自投装置不能自动恢复正常工作电源的需人工进行恢复,不能自重启的辅助设备应手动重启
C.
备自投装置闭锁功能应完善,确保不发生备用电源自投到故障元件上、造成事故扩大
D.
备自投装置母线失压启动延时应小于最长的外部故障切除时间
【单选题】商品批发企业采用数量进价金额核算法时,“库存商品”账户借方登记的是( )。
【单选题】Which of the following is CORRECT about the accident?
A.
The young lady was thrown through the windscreen.
B.
The young lady didn't wear a seatbelt despite Simpson's advice.
C.
The two passengers were driven to hospital by Mr. Simpson.
D.
Simpson's wife got more serious injuries than the young lady.
【单选题】一品红为大戟属的一观赏植物。其最引人注目的是 。
【单选题】A) Looking for a young lady. B) Looking for her wrist watch. C) Looking for a young gentleman. D) Looking for a man wearing a wrist watch.
A.
Looking for a young lady.
B.
Looking for her wrist watch.
C.
Looking for a young gentleman.
D.
Looking for a man wearing a wrist watch.
【简答题】如图所示电路中,已知u S1 =30 sinωtV,u S2 =24V,R=6Ω, 。求:
【单选题】商品批发企业采用数量进价金额核算法时,“库存商品”账户的借方登记的是( )。
【简答题】句型转换。 1. The young lady will have to look after her sick child at home.(改为同义句) The young lady will have to__________ __________ __________ her sick child at home. 2.You should buy me a new car.(改为同义句)...