ONU的PON灯慢闪,LOS灯熄灭,OLT设备不在线,可能是()。
A.PON口错误
B.光衰较大
C.正在同步
D.ONU发光异常
参考答案:A, B
若a为整数,且点M(3a-9,2a-10)在第四象限,则a2+1的值是______
—Jack, do you have anything else to say about the trip?
—No, _______. [ ]
A. anything
B. nothing
C. something
D. everything