当某架信号机开放引导信号时,该信号机在LOW上的符号按信号机基础—机柱—机头的顺序,分别显示为()。
参考答案:黄—黄—红
I think you should go back to your plan, which is much more practical than the present one.
A.original
B.gentle
C.impressive
D.protective
【问题4】 EPON使用什么复用技术