—Did he work out the math problem?        

—No, he thought hard, but could not ______ with a proper answer.[ ]

A. put up    

B. turn up    

C. show up    

D. come up

以下选项中不属于焦炉热量平衡热量出方的是( )。

A．装炉煤物理热
B．焦炭热量
C．水汽热量
D．焦油蒸汽热量