安全气囊（SRS）主要由（）组成。
A．碰撞传感器
B．电子控制单元
C．气囊组件
D．SRS指示灯和螺旋弹簧
参考答案：A, B, C, D
Oh, it's you, I'm sorry I ____know you ____here.
A．don't, are
B．didn't, are
C．didn't ,were
D．don't, were
液压支架最小宽度与最大宽度偏差为±（）mm。
A.20
B.30
C.50
