【单选题】Foam extinguishes a fire by().
A.
smothering the burning material
B.
chemical combination with burning material
C.
absorbing the burning material
D.
organic destruction of the burning material
【单选题】Foam extinguishes a fire by().
A.
shutting off the air supply
B.
cooling the fuel to below ignition temperature
D.
removing the source of ignition
【简答题】常用的压力加工方法有挤压、拉拔、轧制、( )、( )
【多选题】关于箱形截面的凹陷铰折,( )的说法是正确的。
【单选题】Foam extinguishes a fire by().
A.
shutting off the air supply
B.
cooling the fule to below ignition temperature
D.
removing the source of ignition
【判断题】电容器、电感器工作在不同频率时的等效电路不同,工作在低频时宜采用电桥法测量其参数、工作在高频时宜采用Q表法测量其参数。( )
【多选题】关于箱形截面的凹陷铰折,哪个说法是正确的