发生局部冒顶，水量突增并出现流沙，一般是（）突水预兆。
A．老空水
B．断层水
C．陷落柱水
D．松散孔隙含水层
参考答案：D
We saw ____ audience clapping their hands when ______ popular singer appeared on the stage．
A．the; the
B．the; 不填
C．an; a
D．不填; the
D．不构成犯罪
