动物直接或间接地以植物为食，这对植物的生长和繁殖总是不利的．（判断对错）

彼得一世改革的主要目的是（    ）

  “Last week was Road Safety Week at Jason’s school. All the students had to take part in a talk on road safety which was given by a police officer. The following is what the police officer said. ”
  “Most traffic accidents shouldn’t happen. They happen because people are careless. A frequent cause of traffic accidents is speed. Some people drive too quickly. This means that if they have to stop suddenly, they cannot stop quickly enough to avoid （避免）hitting other vehicles （车辆）or people. You need to remember this when you are crossing the street or walking along the sidewalk. ”
  “It's not only drivers who cause accidents, however. People on foot－pedestrians, and bicycle riders often cause accidents, too. Pedestrians sometimes walk out into the street without looking. You should always look on both sides before stepping into the street. ”
  “Do any of you ride a bike? Bicycle riders can cause accidents by changing directions suddenly or without warning other road users. Before you turn left, for example, you should check behind you to make sure there aren’t any cars, trucks or buses coming. You should show with your left hand to tell that you want to turn left. You should not turn until the street is clear. ”
   “The rules of the road are very simple. If we learn them and obey （遵守）them, we should not have accidents any more. ”

（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．