ZXSS10 S100上No.7信令单元第二层（MTP2）处理是通过（）板，第三层（MTP3）处理是通过主控板。
参考答案：信令处理
In ____late 19th century, Europe changed ______great deal and was playing important roles in ______international trade.
A．the; a; the
B．the; the; 不填
C．the; a; the
D．the; a; 不填
在直流电机中（）磁场为零的位置为物理中性线。
A.交轴
B.电枢
C.气隙
D.碳刷
