First ,erosion resulting from excessive deforestation in the upper reaches of the river and ,second ,heavy silting which raised the riverbed in the main channel .

 
  • 第一,过度砍伐引起的河流上游的侵蚀,第二,严重的泥沙淤积抬高了主干道的河床。
今日热词
目录 附录 查词历史