（）是反映社区居民健康状况的重要指标，是社区卫生服务的规划及确定卫生政策的重要依据。 ["人口构成","平均寿命","人口数量","死亡率"]
配电网中性点不接地系统单相接地与电压互感器高、低压熔丝熔断有何区别？
通讯写作表现手法的特点（）。 ["叙述的直接性","描写的直观性","议论抒情的实在性","对话的实录性"]
通讯的结构主要包括几部分（）。 ["标题","导语","主体","结束语"]
When the tilting box of a variable stroke axial-piston pump is perpendicular to the pump shaft, which of the following conditions will exist?（） ["The pistons reciprocate","The ‘B’ end cylinder barrel rotates","There is no fluid flow","Power is transmitted hydraulically"]
变电站母线运行电压越限应如何处理？
