阻尼线花边弧垂的大小,对防振效果影响不大,故在一般档距可采取()。
A、50~l00mm
B、80~l00mm
C、150~200mm
D、150~250mm
参考答案:A
皮肤上沾有低浓度液NH3,会发痒变()。
A、黑
B、折
C、绿
D、红
He likes challenges and he enjoys ________ new ideas. [ ]
A. trying on
B. trying out
C. trying up
D. trying over