下列属虚秘的证型有（）
A.阴虚便秘
B.气虚便秘
C.冷秘
D.血虚便秘
E.阳虚便秘
参考答案：A, B, D, E
— ________was it that David managed to get in contact with the professor?
— Oh, a friend of mine helped him.
A. Where
B. What
C. How
D. Why
疏忽误差一般什么情况下产生的？
