Miss Chen _____ just _____ to speak at the meeting...    [ ]

A. has, been asked    

B. has been, asked

C. have been, asked    

D. have, been asked

建筑火灾的发展分为初起期、发展期、最盛期、减弱期和熄灭期。火灾热释放速率随时间的平方非线性发展是( )阶段的特征。

A．初起期

B．发展期

C．最盛期

D．减弱期