A. 正确 B. 错误
A. 光线路终端(OLT) B. 光网络单元(ONU) C. 光分配网(ODN) D. 机顶盒,电脑,话机等终端
A. a good dictionary should be bought B. buying a good dictionary is necessary C. you should buy a good dictionary D. it is necessary that you will buy a good dictionary