问题
单项选择题
交流供电和（）V以上直流供电的消防用电设备的金属外壳应有接地保护，其接地线应与电气保护接地干线（PE）相连接。
A.12
B.24
C.36
D.50
答案
参考答案：C
解析：本题考查的是系统接地要求。交流供电和36V以上直流供电的消防用电设备的金属外壳应有接地保护，其接地线应与电气保护接地干线（PE）相连接。故此题答案选C。
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交流供电和（）V以上直流供电的消防用电设备的金属外壳应有接地保护，其接地线应与电气保护接地干线（PE）相连接。
A.12
B.24
C.36
D.50
参考答案：C
解析：本题考查的是系统接地要求。交流供电和36V以上直流供电的消防用电设备的金属外壳应有接地保护，其接地线应与电气保护接地干线（PE）相连接。故此题答案选C。
The lady with the white fence（篱笆）taught me to leave the gale to life open.. . My husband died in an accident and I became very angry. I hated being alone. One day, as I was 43 down a busy street, I suddenly noticed a new fence around a house. I pulled off to really watch it. It was such a good 44 that I was deeply touched. I could not send 45 away. The fence still smelled of fresh paint. “Hello!" I came up and said to a lady in the back garden, “I came to see the fence. It's so beautiful!" “Oh! The fence is not there for me," the lady explained to me in a calm voice, “I live alone. _ 46_  so many people pass by every day, and I think they may be pleased to see something really attractive. 47 stop like you and come up to have a chat. ""But weren't you sad when they expanded (拓宽) the road and everything changed so much?" "Change is part of life  and takes part in 48 us who we are. When something we do notlike happens to us, we have two choices—to become a 49 person or to become a better person." Her reply changed my life. I carefully left the gate open and drove on 50 a new feeling inside me. I could not tell 51 it was, but I could feel the thick stone wall around my angry heart breaking off. And 52 a pretty white fence was built. I decided that I would keep the gate open for everything and everyone that came my way.
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