在802.11b模式下,上行或下行单向吞吐量应不低于().
参考答案:不加密
.北京时间2006年7月12日凌晨,中国“飞人”刘翔在瑞士洛桑田径超级大奖赛男子110米栏的比赛中,以12秒88打破了世界纪录!刘翔在比赛中的平均速度约为
A.7.00m/s
B.7.76m/s
C.8.54m/s
D.10.00m/s
She ought to stop working. She has a headache because she ______all day long. [ ]
A. has been reading
B. had read
C. is reading
D. has been read