35. The manager came over and asked the customer how ___________.

A．did the quarrel come about

B．does the quarrel come about

C．the quarrel has come about

D．the quarrel had come about

在通往火区的所有巷道内构筑防火墙，中断空气的供给，使矿井火逐渐自行熄灭，这种灭火方法属于（）。

A.直接灭火方法

B.隔绝灭火方法

C.气体灭火方法

D.综合灭火方法