当地下水在岩土的空隙中运动时，其渗透速度随时间变化，且水质点无秩序地呈相互干扰的运动属于( )。

A．非层流运动的稳定流
B．呈层流运动的非稳定流
C．呈层流运动的稳定流
D．非层流运动的非稳定流

When the earthquake, a destructive natural disaster, happened, ninety-nine coal miners were trapped

in the coal mine _____the ruins, waiting _____. [ ]

A. in; to be rescued  

B. under; for being rescued

C. in; to rescue  

D. under; to be rescued