如图，在直角梯形ABCD中，AD∥BC，∠ABC=90°，BD⊥DC，BD=DC，CE平分∠BCD，交AB于点E，交BD于点H，EN∥DC交BD于点N．下列结论：
①BH=DH；②CH=($\sqrt{2}$+1)EH；③$\frac{S_{△ENH}}{S_{△EBH}}$＝$\frac{EH}{EC}$．其中正确的是（　　）

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    London is the capital of England. It is a very big____(城市). There are____(三) beautiful parks in London. And there is a zoo in one of the parks. The zoo is____(很棒的) . There are many animals from Africa,____（亚洲），America and Europe in the zoo. At____(周末) , we can see lots of people in the parks. Some children like to play football or take____（照片）. Some like to listen to____（音乐）or talk with friends. Their parents can read books on the chair or____（散步，步行）near the river. Look! Over there! Some girls____（跳舞）and two birds are singing for them . Some boys are playing the guitar near the____（高的）tree. Everyone is happy.

如图所示，A、B中人站在地面上，C、D中人站在干燥的木凳上，则人会触电的是

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1917年著名盲聋作家海伦·凯勒热情欢呼“在东方，一颗新星冉冉升起！在痛苦的挣扎中，新秩序从旧的秩序中降生。看哪！在东方，一个男婴降生了！”这个历史事件发生在