— What Jack wore that day was very strange.

— Yes. I didn't     him until he called my name.

A．realize

B．recognize

C．know

D．believe

焦炉加热时，使用下列（）加热时耗热量低，系统阻力小。

A、高炉煤气

B、焦炉煤气

C、高炉和焦炉的混合煤气