题目

You Mi, a lovely and confident 17-year-old student, is the first Chinese high school student to appear on the cover of the popular young adults’ fashion magazine Seventeen.“You is IN,” said Wang Lihua, Editor-in-Chief of Seventeen. “She is active and mature(成熟的) because of her knowledge on everything from academic studies, to books on art, to movies. We found she’s the very style we’re looking for to represent young people’s attitudes.”You also impressed Wang with her fluent English when they first met last year. As the hostess of an English broadcasting programme at the (2007，甘肃省六市，22)如图，阳光通过窗口照射到室内(太阳光线是平行光线)，在地面上留下2.7m宽的亮区(如图所示)，已知亮区到窗口下墙脚的距离EC=8.7m，窗口高AB=1.8m，求窗口底边离地面的高BC．