植物为什么不向下长?星期六,白老师带小朋友们到野外去郊游。白老师说:“看,大树发芽了,小草长高了,花儿开放了,多美!”小好问说:“白老师,小草为什么不向下长呢?”“小好问提了一个有趣的问题。”白老师说,“植物的根向下生长是因为受到地心引力的影响,这种习性叫做向地性。” Why plants do not grow down? On Saturday, White teacher took the children to the wild to go hiking. White teacher said: “Look, the tree sprouted, the grass grow taller, the flowers are open, the beautiful!” Little asked: “White teacher, why the grass does not grow down?” “Small good asked a very interesting question. ” White said, “The roots of plants grow because of gravity, this habit is called to the nature. ”