日本是太平洋上的一个群岛国家,本州、北海道、九州、四国4个岛最大,约占日本陆地面积的98％。日本为了把本州与四国连接起来,正在修建“本四联络桥”。本四联络桥由3条桥线组成:神户——鸣门线、儿岛——坂出线、尾道——今治线,堪称世界上最大的海上桥群。其中,儿岛——坂出线位于3个桥线的中间,被称为濑户大桥,已经建成通车。濑户大桥由11座桥梁组成,既有悬索桥, Japan is an archipelago in the Pacific Ocean. The four islands of Honshu, Hokkaido, Kyushu and Shikoku are the largest, accounting for about 98% of Japan’s land area. In order to connect the prefecture with the four countries, Japan is building “the fourth bridge.” The four bridges consist of three bridge lines: Kobe - Naruto Line, Kojima - Sakae Line, Onomichi - Imabari line, called the world’s largest sea bridge group. Among them, Kojima - Sakae line located in the middle of the three bridge lines, known as Seto Bridge, has been opened to traffic. Seto Bridge consists of 11 bridges, both suspension bridge,