ZXMSG 9000设备上用来进行MTP3层以上信令处理的的单板是（）.
A.DTB
B.OMP
C.MPX86
D.SPB
参考答案：C
It was in the street _______ I met one of my friends yesterday.
A．how
B．that
C．which
D．when
金属材料切削性的好坏，主要取决于其韧性。
