Tropical area短语¹⁴⁴⁹⁷²⁺² 基本例句 热带地区 The seasonal development of secondary phloem of23 species of deciduous trees distributed naturally or introduced on Hainan Island in tropical area of China was studied using microscopy. 用显微技术研究了海南岛天然分布和引种的23种落叶树木次生韧皮部的季节发育。 cnki