非洲沙漠地区生长着一种奇特的植物——光棍树。它一年四季只长树干枝条,不长叶子,光秃秃的,如枯木一般。然而,这死一般的树木却是生机蓬勃的,以一种特有的姿态长驻在茫茫沙漠之中。光棍树是为了适应非洲荒漠地带干旱的气候才逐渐退化了叶子,用绿色的茎和枝条进行光合作用的。如果它也像气候湿润、雨水充足地方的植物一样,长出又大又多的叶子,那么它会因叶子的蒸腾作用而丢失大量水分,从而无法适应干旱而 An exotic plant, bachelor tree, grows in the African desert. It is a long tree branches throughout the year, not long leaves, bare, such as dead wood in general. However, this dead tree is thriving, with a peculiar gesture of long standing in the vast desert. The bachelor tree was gradually degenerating leaves and adapting green stems and shoots for photosynthesis in order to adapt to the arid climate of the African desert. If it also grows bigger and bigger leaves, like plants in a humid, well-rained place, it will lose a lot of water due to leaf transpiration and will not be able to adapt to drought