能够产生高电压脉冲以激发探头工作的电路单元是放大器。
参考答案：错
——Lily is going to make a presentation in class this afternoon.
—Oh, really? I _____it was Michael’s turn.
A．think
B．have thought
C．thought
D．am thinking
按下控制电气柜里的辅助压缩机起动按钮，辅助空气压缩机起动辅助风缸的气压上升到（）kPa时，辅助空气压缩机自动停止。
A.650
B.735
C.900
