如图，在梯形ABCD中，AB∥CD，⊙O为内切圆，E为切点．若AO=8cm，DO=6cm，求OE的长．

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一束与镜面成45°角的水平光线射在平面镜上，如图所示．请在图中画出反射光线并标明反射角的大小

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阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。

      As we all know, games play a very important role in the growth of children. Children should grow along with playing games; for, ____ playing games, they can not only acquire knowledge, but also develop their abilities to get along with others.

      However, most children are ____(face) with a completely different situation. Most parents fear that games will prevent children from increasing new knowledge and ____ the children will fail in the future examinations. So, instead of____ (let) the children themselves find and learn naturally from their surroundings, they force their children to take part in____ (variety) kinds of classes, learning English, playing____ piano or practicing drawing, etc. What's more, some parents put away the children's toys which are very useful in developing children's ____ (imagine) and practical abilities.

      Here is a piece of good advice to those parents: ____ you want to expect your child to be able to accomplish something, you must first of all develop his ability to adapt ____ the new surroundings. That cram (填鸭式的) education can lead to nothing ____ a failure in the children's growth.

材料一  “西洋人因为拥护德、赛两先生，闹了多少事，流了多少血，德、赛两先生才渐渐从黑暗中把他们救出，引到光明世界。我们现在认定只有这两位先生，可以救治中国政治上、道德上、艺术上、思想上一切的黑暗。”

——陈独秀

材料二  李大钊指出俄国革命是“立于社会主义上之革命”“是世界人类全体的新曙光”，我国人民应该向俄国学习。