【Abstract】Textbook plays a very important role in secondary schools. By fully understanding its characteristics， teache......

华北地区地处北温带气候区.幅员辽阔,地形复杂,气候多样,植物资源极其丰富,尤其刺生树种资源,以其丰富性、重要性,成为我国绿色资......

以内质多刺植物霸王鞭(Euphorbia royleana)和仙人掌(Opuntia monacantha)为特征的具有荒漠植被景观的元江干热河谷肉质多刺灌丛是......

Shrub species have a great capacity to develop in extreme climatic conditions;this ability has a direct influence on the......