（2014·绍兴）如图，表示镁、铜与其氧化物的质量关系。图线不重合的原因是  (    )

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综合题。

读图，完成下列要求．

完形填空

    Fred is a bus driver. He always drives the number 14 bus. Fred's bus goes 1the shopping mall on High Street to the park on Queen Street, then 2to the shopping mall. Fred3work at six o' clock every morning.4 bus leaves the shopping mall at ten past six. Fred is sometimes5 to work. When he is early, he sits in his bus and6the newspaper until it's time to go. Fred always stops for 7on the bus because he has to finish work at three o'clock in the afternoon. He doesn't go home by bus. He 8 ! He thinks it's really good for his health. Fred loved his 9 because he can meet different people every day. And he is very10. So the people who travel on Fred's bus like Fred very much.

如图是一座人行天桥的引桥部分的示意图，上桥通道由两段互相平行并且与地面成37°角的楼梯AD、 BE和一段水平平台DE构成。已知天桥高度BC≈4.8米，引桥水平跨度AC=8米。

（1）求水平平台DE的长度；
（2）若与地面垂直的平台立枉MN的高度为3米，求两段楼梯AD与BE的长度之比。
(参考数据：取sin37°=0.60，cos37°=0.80，tan37°=0.75