IEEE802将数据链路层划分为两个子层，上子层是LLC，下子层是MAC。
参考答案：对
—How was your school trip, Mingming?
—t was _____.We had a great time there.
A. fantastic
B. important
C. boring
D. strange
癫痫的年发病率为（）
A.50%～70%
B.50‰～70‰
C.50／万～70／万
D.50／10万～70／10万
E.50／100万～70／100万
