将燕麦幼苗的胚根及胚芽末端4mm切去，再将剩余的10mm的胚根及胚芽每10条一组分别放人保持在25℃的不同浓度的生长素溶液中2d，表显示实验结果：

（1）此实验的实验目的是研究____ 

（2）为什么要切取胚根及胚芽的末端部分？____ 

（3）为什么要用10条一组而不是1条一组放入生长素溶液中进行实验？____ 

（4）胚根、胚芽的最适生长素浓度分别是____ 　、____ 

（5）实验可得出的结论有____ 

世界政治现代化的过程，渐进缓慢、曲折艰难。阅读下列材料，回答问题。
材料一  中国几千年来，政权归皇帝一人掌握。皇帝具有至高无上的权力，表现为高度的中央集权，这是占主导地位的制度。
——张岂之著《中国文明史十五讲》

材料二  英国用“光荣革命”的非暴力手段建立了一种新的政治制度……新制度营造出一种宽松、自由和开放的环境…… 
——钱乘旦著《世界现代化历程》

材料三  其基本精神按照西方资产阶级民主制度和三权分立的原则，在中国建立了一个实行议会制和责任内阁制的资产阶级共和国……革命党人希望借此来限制袁世凯，束缚他专制独裁的手脚……
——卢菡著《不可不读的中国历史》

材料四  1982年，第五届全国人民代表大会第五次会议通过了新的《中华人民共和国宪法》。新宪法成为推进我国改革开放和社会主义现代化建设事业的根本大法。
——岳麓书社八年级下册《中国历史教学参考书》

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