【判断题】抗原分子刺激机体产生免疫应答(产生特异性抗体及免疫效应细胞)的性质即免疫原性。
【单选题】设 , ,则与向量 , 同时垂直的单位向量为( ).
【单选题】设 , ,则与向量 , 同时垂直的单位向量为( ).
【单选题】Which of the following should be the FIRST step in removing a generator from parallel operation?
A.
Trip the generator off the switchboard
B.
Turn off all electrical equipment
C.
Remove the load from the 'off going' generator
D.
Increase the cycles of the generator staying on the line
【简答题】共集电极放大电路与共发射极放大电路相比,有何不同?电路有何特点?
【单选题】Which is false about engine trials?
A.
engine trails should be done after finishing the operation of turning the engine with the turning gear and starting the engine on air briefly
B.
in the operation of engine trails, the main engine should be running in low-speed
C.
As to the ship equipment with twin main engine, engine trials should be done with one engine ahead and another engine astern at the same time
D.
the order “engine trials” should be given by the bridge
【简答题】与共射放大电路相比,共集电极放大电路(射极跟随器)的输入电阻____,输出电阻 ____,电压放大倍数约为____。
【简答题】液压马达是 将 _______ 转换成 _______ 的转换元件。 2. 液压马达属于 _______ 元件。 3. 液压马达根据结构分为 _______ 、 _______ 、柱塞马达。 4. 液压马达根据工作速度不同分为 _______ 和 _______ 。 高速马达包括齿轮马达、 _______ 和 _______ 。