用于表明货物所处业务状态或阶段表示的货卡是（）
A.状态卡
B.储存卡
C.标识卡
D.储存期限卡
参考答案：A
计算：（3a﹣2b）（3a+2b）．
You'd better wake him up at once. He _____ for eleven hours already. [ ]
A. has been asleep
B. has fallen asleep
C. has gone to bed
D. has gone to sleep
