附属卡升级主卡需（）持本人有效证件办理。
A.主卡持卡人和附属卡持卡人
B.附属卡持卡人
C.主卡持卡人
参考答案：B
Personal computers _______ in 1976. It has changed the whole world. [ ]
A. have been invented
B. are invented
C. were invented
D. invented
龙骨和牡蛎的共同功效是
A．平肝潜阳
B．软坚散结
C．收敛固涩
D．镇惊安神
E．制酸止痛
