当水温接近最高允许温度时，应采取措施（），一旦出水温度超过此值应立即紧急停炉。

A、加强燃烧

B、提高回水温度

C、减弱燃烧

D、提高压力

When dry chemical extinguishers are used to put out class B fires，there is a danger of reflash because dry chemical（）.

A.is not an effective agent on Class B fires

B.does little or no cooling

C.dissipates quickly

D.is rapidly absorbed by the liquid