OTN中的OTUk帧由哪几部分组成？（）
A.ODUk帧
B.OTUk FEC
C.OTUk开销
D.FAS
参考答案：A, B, C, D
Did the boy ________forward to buying a new football? [ ]
A. referred to look
B. refer to look
C. referring to looking
D. referred to looking
具有小巧、轻缓、柔和等形式特征的审美形态是（）
A．优美
B．崇高
C．荒诞
D．乖巧
