读“日本、俄罗斯、巴西”三国示意图，完成下列问题。

① $\sqrt{2}$ ﹣1与2﹣ $\sqrt{3}$ ；②2﹣ $\sqrt{3}$ 与 $\sqrt{6}$ ﹣ $\sqrt{5}$ ；

（Ⅱ）类比以上结论，写出一个更具一般意义的结论，并给出证明．

将左边和右边的句子连成对话。

①Is this your bed? ____           a. Hi, Joe.

②Are these your pens? ____    b. No, it isn't.

③Your book is nice. ____        c. Thank you.

④Hi, Peter. ____                      d. Six yuan, please.

⑤How much are they? ____     e. Yes, they are.