一说起草原，就会使人想起天苍苍，野茫茫，风吹草低见牛羊的动人景象。我国内蒙古以及东北地区有着大片的草原。辽阔美丽的草原，宛如一幅堆绿叠翠，碧波浩瀚的图画。在那里，除了一些多年和草本植物或灌木林丛外，却见不到一棵象样的树。草原上怎么不长树呢?人们经过长期的科 When we talk about the grassland, people will remember that the sky is pale, the wild grass, and the wind blows grass and sees the moving sight of cattle and sheep. China’s Inner Mongolia and Northeast China have large grasslands. The vast and beautiful grassland resembles a picture of green emerald and blue waves. There, there was no decent tree except for a few years with bushes of herbs or shrubs. How is the tree not grown on the grassland?