在爆炸危险环境中，应当在爆炸危险性较小或距离释放源较远的位置敷设( )。
A．电气线路
B．防爆钢管配线
C．电缆配线
D．照明线路
参考答案：A
﹣7+（ ）=21．
As we are _____ Table Cloth, we should be pleased if you would send us your best quotations.
A．in the market for
B．on the market for
C．entering the market for
D．at the market for
