大多数肛门直肠脓肿感染的门户是
A．齿线
B．肛 * *
C．肛腺管
D．肛隐窝
E．肛门直肠周围间隙
参考答案：D
25的平方根是（ ），0.04的算术平方根是（ ），-8的立方根是（ ）。
29. A big earthquake hit Yushu, Qinghai province in the early morning, and if a little later, many more people _______.
A．could survive
B．might have survived
C．must have survived
D．should survive
