【单选题】Combustible gas indicators operate by drawing an air sample into the instrument().
A.
over an electrically heated platinum filament
B.
where it is mixed with nitrogen
C.
where it is ignited by a sparking device
D.
where its specific gravity is measured
【单选题】Using Your Tumble-Drier(滚筒烘干式洗衣机) Controls Timer(计时器)Control To operate the drier, close the door and turn the timer control to the required. The timer can be set to any time up to 120 minutes and can...
【单选题】容积为 V =0.027m 3 的刚性储气筒内装有压力为 0.5MPa 、温度为 27 ° C 的氧气。筒上装有一排气阀,压力达到 0.8MPa 时就开启,压力降为 0.75MPa 时才关闭。若由于外界加热的原因造成阀门开启。 若筒内气体温度在排气过程中保持为阀门刚开启时温度不变,那么因加热而损失掉的氧气质量是多少 kg ?氧气的气体常数 R g =260 J/(kg.K) 。
【单选题】词汇与结构 Either hydraulic system A or B can operate all primary flight controls. Ailerons and elevators can be operated _________ if required.
【单选题】将 6mA 转换为 A ,得到 ( ) 。