构音检查语音标准音为()
A.北京话
B.东北话
C.普通话
D.闽南话
E.受检者方言
参考答案:C
阀门定位器一般在阀前后差压大于()的场合,用在流体中含有()、高粘度以及用于口径为()以上的调节阀上。
There were few people living here ___ because it was too cold.
A.at any time
B.at times
C.at a time
D.at no time