As soon as he comes back, I’ll tell him when _______ and see him.

A．you will come

B．will you come

C．you come

D．do you come

关于爆炸极限下列说法错误的是（）。

A．爆炸极限是评定可燃气体火灾危险陛大小的依据 

B．爆炸范围越大，下限越低，火灾危险性就越大 

C．根据爆炸极限可以确定建筑物耐火等级、面积、层数 

D．生产、储存爆炸下限>10％的可燃气体的工业场所，应选用隔爆型防爆电气设备