关于移动电话通信的信令，与PSTN信令相同的是（）之间的信令.
A.MS至BS
B.BS至MSC
C.MSC至PSTN
参考答案：C
(2012·山东)My first ________ of him was that he was a kind and thoughtful young man.
A．expression
B．attention
C．satisfaction
D．impression
化石按体积大小分为（）；（）、超微化石、分子化石。
