如图所示，在△ABC中，DE是AC的垂直平分线，AE=3cm，△ABD的周长为13cm，则△ABC的周长为（ ）cm．
19
Miss Zhao is very helpful. She often helps us ____we are in trouble. [ ]
A. whether
B. although
C. whenever
D. however
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
