自动控制系统中测量被控量并进行信号转换，再反馈到输入端的元件是（）。
A.比较元件
B.校正元件
C.测量反馈元件
D.执行元件
参考答案：C
It was not the cyclist but the driver who ________ for the traffic accident.[ ]
A. was blamed
B. was to blame
C. was to be blamed
D. were to blame
下列哪项不是神经根型颈椎病症状（）
A.颈僵活动受限
B.头、枕、颈痛
C.手麻
D.下肢无力、步态不稳、手足颤动
E.肘部痛、胀
