（一）方法步骤

取6个小花盆，各栽入一株品种、粗细和大小都相同的玉米幼苗（要求幼苗的真叶未突破胚芽鞘）．按如图所示方法进行实验处理．接通台灯电源24h后，打开纸盒，观察并记录6株玉米幼苗的生长情况．

（二）实验结果预测

在以上装置中，玉米幼苗保持直立生长的是____装置，而玉米幼苗基本停止生长的是____装置．

（三）部分实验结果的分析与推论

①根据____和____号装置之间实验记录的对照分析，可以说明玉米幼苗产生向光性是由单侧光照射引起的．

②根据____和____号装置实验记录的对照分析，可以说明玉米幼苗的向光性生长与玉米幼苗尖端的存在与否有关．

③根据1和4号装置实验记录的对照分析，可以说明____．

Ⅳ主要植物激素除生长素、赤霉素以外还有____、脱落酸、乙烯．其中生长素的合成部位是____．在这些部位，____经过一系列的反应可转变为生长素．

    University of Oxford is the oldest university in the English-speaking world and it's one of the top universities in the world. There is no clear date when the university started, but teaching began at Oxford in some forms in 1096 and developed quickly from 1167.
    There are 39 independent（独立的）colleges at Oxford, attracting students and learned men from across the world. There are over 100 libraries for the students and learned men to use. At University of Oxford, they also provide a number of money for the best students. Of course, if you want to study here, first you have to reach a certain level of English language.
    College life at Oxford is very exciting but busy. The groups of college provide a friendly and welcoming home for students while the colleges are strict with students about their studies. Many Chinese students are studying here. The number of Chinese students at the university has grown quickly over the past 10 years.
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下列各句中，划线的成语使用恰当的一句是（　　）