根据《火电厂大气污染物排放标准》(GB13223-2003)对火电厂大气污染物的监测,应在机组运行负荷的()%以上时进行。
A.70
B.75
C.80
D.85
参考答案:B
—Why didn't you come to the cinema with us last Saturday?
—Oh, sorry.But I________the film.[ ]
A. see
B. saw
C. have seen
D. had seen
浓缩的真空主要是由()产生的。
A、氟循环泵的喷淋
B、尾气冷凝器酸性循环水的抽吸
C、尾气冷凝器酸性循环水对蒸汽的吸收