集装箱上有哪些标记？
参考答案：有箱主代号、顺序号、核对数字、国家或地区代号、总重和自重。
—Is Bob still teaching?
—I’m afraid not. He is said the school as he has become a businessman.
A．that he has left
B．to leave
C．to have left
D．to be left
本地主机房的建设设计等级为A级，则异地建设的备份机房等级是（）。
A.A级
B.B级
C.C级
D.D级
