在加热炉内零压线位于加热钢坯的（）。
A.上端面
B.下端面
C.炉顶
参考答案：B
下列哪组试剂在使用的过程中必须加热[ ]
A．斐林试剂鉴定还原糖
B．苏丹Ⅲ染液鉴定脂肪
C．双缩脲试剂鉴定蛋白质
D．健那绿对活细胞线粒体染色
The reason why she came here late this morning was she had to look after her sick daughter.
A．why
B．because
C．that
D．because of
