制动器的（）疲劳、材料老化或产生裂纹、无弹力。将导致张力减小、制动力矩减小。
A、制动轮
B、芯轴
C、弹簧
D、瓦衬
参考答案：C
With my work _______ early today, I am able to enjoy a happy night with my family.
A．finish
B．finished
C．finishing
D．to finish
肺癌( )
A．X线胸片见单个薄壁空洞B．X线胸片呈大片状阴影，内为单个空洞伴液平C．X线胸片有偏心空洞，内壁凸凹不平D．X线胸片上肺有小片状阴影伴空洞E．X线胸片呈大片状阴影，呈肺叶或肺段分布
