控制器到位时应使阻力发生一种变化，作为反馈信息传达给操纵者。这种变化可以是操纵到位时阻力突然变小或阻力突然变大两种情况。
参考答案：对
Mrs Linda has ____ that she is unable to get a job. [ ]
A. such little education
B. so little education
C. a such little education
D. so few education
耳根毒相当于化脓性中耳炎的哪种并发症：（）
A.耳后骨膜上脓肿
B.耳疔
C.耳后骨膜下脓肿
D.耳后骨膜脓肿
E.耳后骨膜间隙脓肿
