转炉炉体支承系统包括（）。
A.托圈
B.炉体和托圈的连接装置
C.耳轴
D.耳轴轴承
E.轴承座
参考答案：A, B, C, D, E
.It is said that pandas ___________ in our country year after year.
A．are being disappeared
B．are disappearing
C．will be disappeared
D．will disappear
()不是钢电弧焊时氢的危害。
A．产生气孔
B．产生白点
C．引起氢脆
D．引起热裂纹
