集装箱也属于一种（）。
A.包装
B.包装箱
C.大型包装箱
D.混合包装
参考答案：C
Experts have been warning _____ of the health risks caused by passive smoking.
A．at a time
B．at one time
C．for some time
D．for the time
简述错账的更正方法及使用范围。
