Re小,表明流体中黏性力的作用较小,能消弱与消除引起流体质点发生乱运动的扰动,使流体保持平静的层流状态。
参考答案:错
Could you say ______ about it, please ? I'd like to know more.[ ]
A. nothing else
B. anything else
C. something else
D. something other
牙龈出血可能是缺乏以下哪种维生素引起的()
A.维生素A
B.维生素B
C.维生素C
D.维生素D
E.维生素E