2. The sentence is "Looking down from the air, Hainan Island looks like a Sydney; Seen from the sea, the island is shaped like an open umbrella, with a high center and gradually decreasing heights around it. The center of the umbrella is the towering Wuzhishan. " It uses metaphor, and its advantage is that it vividly describes the shape and characteristics of Hainan Island.

The third paragraph of the article plays a transitional role in the text, so it is called transitional paragraph.

4. In the second paragraph of the article, first write "Hainan Island is a treasure island", then write that Hainan Island is rich in product resources, and finally write "Hainan Island is a huge treasure house". This is a "total score" structure.