消防专用电话、电话插孔、带电话插孔的手动报警按钮宜安装在明显、便于操作的位置;当在墙面上安装时,其底边距地(楼)面高度宜为()m。
A. 1.3~1.5
B. 1.3~1.6
C. 1.1~1.5
D. 1.2~1.5
It was well known that Thomas Edison()the electric lamp.
A. invented
B. discovered
C. found
D. developed
下面那一项()对中继群去话应答占用比统计结果不产生影响。
A. 对端拥塞;
B. 久叫不应;
C. 溢出;
D. 呼叫失败。