高频同轴电缆应在两端（），并在靠近敷设处截面（）mm2。
参考答案：分别接地；不小于100
开放作文。
请根据下面提示，写一篇短文。词数不少于50。
In your English class, the teacher shows the picture below and asks the class to discuss it. Your
classmates may have different understandings.
Look at the picture carefully and tell the class how YOU understand it.
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社会保障的核心层次是
A．社会福利
B．社会优抚
C．社会保险
D．社会救助
