压差阻力
参考答案：
由于流动时流束变形以及涡旋的出现等原因，在物体的前方和后方产生压强差所引起的阻力，称为压差阻力。
--- Oh, my God! We just missed the last bus back home.
--- I’m sure we it, but you were not in any hurry.
A．could catch
B．had caught
C．would catch
D．could have caught
0.06中的“6”表示6个0.1。[ ]
