导致胆囊结石死亡的并发症是（）
A.胆囊炎
B.胰腺炎
C.胆管炎
D.胆绞痛
E.结石胆囊嵌顿
参考答案：C
如果减数为负数，则（ ）
A．差比被减数小
B．差比被减数大
C．差为正数
D．差为负数
—Can you guess _____ the MP4 player yesterday?
—Sorry, I've no idea about it. [ ]
A. how much did he pay for
B. how can he get
C. how much he paid for
D. how he has got
