筒式减振器的异响成因有（）。
A、摩擦撞击异响
B、共振异响
C、截流和气体异响
D、减震器发热
参考答案：A, B, C
–Shall we go out for a walk?
–Sorry. This is not the right __ to invite me. I am too tired to walk.
A．moment
B．situation
C．place
D．Chance
