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4月26日,2015黄河口(东营)国际马拉松比赛拉开帷幕,中央电视台体育频道用直升机航拍技术全程直播.如图,在直升机的镜头下,观测马拉松景观大道A处的俯角为30°,B处的俯角为45°.如果此时直升机镜头C处的高度CD为200米,点A、D、B在同一直线上,则AB两点的距离是____米.
It's difficult for the village children to cross the river to get to school. We think a bridge________ over the river
I was very .I tried to keep my eyes open but I couldn’t.