The scientist calls on the world ______ weather change as well as the protection of endangered animals.  (pay)

某班同学用如下实验探究、的性质。回答下列问题：
（1）分别取一定量氯化铁、氯化亚铁固体，均配制成的溶液。在液中需加入少量铁属，其目的是_____。
（2）甲组同学取溶液．加入几滴氯水，再加入滴溶液，溶液变红，说明可将氧化。溶液与氯水反应的离子方程式为_____。
（3）乙组同学认为甲组的实验不够严谨，该组同学在溶液中先加入煤油，再于液面下依次加入几滴氯水和滴溶液，溶液变红，煤油的作用是_____。
（4）丙组同学取溶液，加入溶液混合。分别取此溶液于支试管中进行如下实验：
   ①第一支试管中加入充分振荡、静置，层呈紫色；
   ②第二只试管中加入滴溶液，生成蓝色沉淀；
   ③第三支试管中加入滴溶液，溶液变红。
   实验②检验的离子是_____（填离子符号）；实验①和③说明：在过量的情况下，溶液中仍含有_____（填离子符号），由此可以证明该氧化还原反应为_____。
（5）丁组同学向盛有溶液的试管中加入几滴酸化的溶液，溶液变成棕黄色，发生反应的离子方程式为_____；一段时间后．溶液中有气泡出现，并放热．随后有红褐色沉淀生成。产生气泡的原因是_____；生成沉淀的原因是_____（用平衡移动原理解释）。

    Peter loved to shop used articles. Almost a month ago, he bought popular word game that used little pieces of wood with different letters on them. As he was purchasing it, the salesgirl said, “Uh, look, the game box haven’t even been opened yet. That might be worth some money. ”
    Peter examined the box, and, sure enough, it was completely covered in factory-sealed plastic. And he saw a date of 1973 on the back of the box.
    “You should put that up for auction (拍卖) on the Internet, and see what happens.”the salesgirl said.
    “Yes, you’re right. People like something rare.” Peter agreed, “I can’t imagine there being very many unopened boxes of this game still around 40 years later.”
    “Don’t forget to tell me if you sell it.” the salesgirl smiled.
    “No problem.” Peter said.
    After he got home, Peter went online to several auction websites looking for his game. But he couldn’t find it. Then he typed in the name of the word game and hit Search. The search result was 543 websites containing information about the changes of the game. Over the years, the game had been produced using letters in different sizes and game boards in different colors. He also found some lists of game fans looking for various versions of the game. Peter emailed some of them, telling them what he had.
    Two weeks later, Peter went back to the shop.
    “Hello. Do you still remember the unopened word game?”
    The salesgirl looked at him for a second, then recognized him and said, “Oh, hi!”
    “I’ve got something for you,” Peter said. “I sold the game and made $1,000. Thank you for your suggestion.” He handed her three $ 100 bills.
    “Wow!” the salesgirl cried out. “Thank you, I never expected it.”