Effects of usnea longissima polysaccharide on immunologic function in mice 长松萝多糖对小鼠免疫功能的影响
2.
All day the sun has shone on the surface of some savage swamp ， where the single spruce stands hung with usnea lichens ， and small hawks circulate above ， and the chickadee lisps amid the evergreens ， and the partridge and rabbit skulk beneath ； but now a more dismal and fitting day dawns ， and a different race of creatures awakes to express the meaning of nature there 整天，太阳曾照在一些荒野的沼泽表面，孤零零的针枞上长着地衣，小小的鹰在上空盘旋，而黑头山雀在常春藤中蹑嚅而言，松鸡、兔子则在下面躲藏着；可是现在一个更阴郁、更合适的白昼来临了，就有另外一批生物风云际会地醒来，表示了那里的大自然的意义。
