下列哪层不是牙本质龋的病理变化（）
A.透明层
B.脱矿层
C.再矿化层
D.细菌侵入层
E.坏死崩解层
参考答案：C
Much to our surprise, the witness's ________ of the traffic accident differed from the official version in several aspects.
A．account
B．opinion
C．instruction
D．explanation
小张丢失的手机若被小刘通过拍卖购得，小张向小刘索要时不需支付费用。 ( )
