自动喷淋系统在以下哪个设备报警时才启动喷淋加压泵（）
A、信号蝶阀报警
B、压力开关报警
C、水流指示器报警
参考答案：B
影响平版印刷质量的因素有（ ）等。
A．纸张、油墨的印刷适性
B．印版的质量
C．印刷机的精度
D．油墨透过网眼的速度
E．印刷色序
It is the third time that she ______ the role of Juliet ever since she graduated from university.
A．has played
B．had played
C．is playing
D．played
