下图示意我国植被的地带性分布。读图完成下列问题。

图中②为（   ）

在确定苯的结构的研究过程中,曾经有下列结构:a． 　、b． 。

请回答下列问题:

   The first telephone cards, produced in 1976, were Italian. Five years later the first British card appeared, and now you can buy cards in more than a hundred countries. People usually start collecting cards because they are small and light and you do not need much space for them. It is also a cheap hobby for beginners, although for some people it becomes a serious business. In Paris, for example, there is a market where you can only buy telephone cards, and some cards cost up to ￡4,000.The first Japanese card has a value of about ￡28,000. Most people only see cards with prices like these in their collectors' magazine.

***在天津考察时曾指出：“民生没有终点，只有新起点。”19世纪60年代，俄国亚历山大二世改革和日本明治维新共同关注的民生问题是（　　）