泵在运行中,如发现供水压力低、流量下降、管道振动、泵窜动,则为()。
A.不上水
B.出水量不足
C.水泵入口汽化
D.入口滤网堵塞
参考答案:C
But Obama’s appearance presented a deeper challenge, reflecting the tenor of his times. Unlike those tragedies---which, at least initially, united a mournful country and quieted partisan divisions---this one has, in the days since the killings, had the opposite effect, inflaming the divide.