当液体流过调节阀，在节流口流速急剧上升，压力下降，若此时压力下降到低于液体在改温度下的饱和蒸汽压便会汽化，分解除气体后形成液双向流动，这种现象叫（）。

A.闪蒸

B.空化

C.气蚀

D.腐蚀

It is said that a certain careless operation ____ the terrible fire in Shanghai in Nov.15.

A．resulted from

B．resulted in

C．turned out

D．worked out