 Complete the following phrase:  To diversify the local economy, tourism had become another major source of income. The annual average temperature is , and the climate is typical subtropical climate. The forest coverage rate is greater than 56 and it is the provincial level forest park. Due to the forces of nature such as that of tides and winds, there are many spectacular sceneries and the archipelago is called the Chinese Number One Oceanic Penjing Zhong-Guo Di-Yi Hai-Shang Penjing, 中国第一海上盆景. Another tourist attraction was the military fortifications left behind by the nationalists during the Chinese Civil War in the post-World War II era, because the archipelago was the site of the Battle of Dachen Archipelago in the 